Topic: [Antminer S1 Sales open] Price changes daily, now 0.414 BTC for 180GH/s - page 76. (Read 346284 times)

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM

Quote from: ZiG on April 12, 2014, 12:29:18 AM

Anyone running 3 S1 on a seasonic? I need help!

I keep getting the psu going into some sort of protection mode...ie no power after running for 10 minutes.

My PCI-E are plugged into the lower right 3 PCI-E slots.

Running 2 units seems ok. PSU is 1250W, 2 units stock, 1 unit OC 375.

There probably isn't enough power on the 12V rail to run 3 S1s. Check the specs of your PSU.

I'm running 3 OC'd S1s on a Rosewill 1300 gold and pulling about 1215 watts. Mine is rated at 108A on the 12V rail. > 87% efficiency, up to 92%.

M

I have a corsair AX1200 that is running on 213V power. It is able to handle 3 antminers tuned to 387.5MHz each. (I tuned one down to 381MHz to slightly lessen the load and because that one unit was just over 1% hw errors)

I think it's the 220V that makes the difference. Based on what I'm seeing with my 1300 @ 115V, I don't see how a 1200 would cut it @ 115V.

M

All of this discussion about the overall wattage of the PSU, line (mains) voltage, PSU efficiency, etc is driving me crazy (and it's a short ride for me). Here is how I see it.

PSUs have one or more rails that deliver +12V; the 12V rail(s) has/have a max rated amperage; the 12V rail is the only "part" of the PSU the S1 uses; therefore overall PSU "wattage" is not a limiting factor. If the Ants you connect to a PSU draw more power than the PSU's rated +12V amperage, you will shut down the PSU (best case). We can express "power" in this case as amps since we know we are always talking about a 12V system.

Bitmain says the S1 draws "360W from the wall". To give ourselves some headroom / room for error and variability, let's assume a non-overclocked S1 draws 30A (360w / 12V) from the +12V rail. If the BM statement is accurate, you will actually draw less than 30A at the 12V rail(s), but that's OK, we want a margin for error / variability in the amount of power we think the S1 draws. [Note if anyone has actually measured the amps drawn at the 12V rail, we can significantly refine our calculations]

Therefore, if you have three non-OC'd S1s on a given PSU, it better have at least a 90A rating on +12V rail. Looking at the BM chip spec and doing a little math, it appears that if an S1 is OC'd to 400MHz it will draw just over 38A. If you are connecting three S1s OC'd to 400MHz, your PSU should be rated at 115A on the 12V rail(s).

We may have built in more headroom than necessary (we essentially assumed the PSU is 100% efficient, which is clearly impossible) and you may be able to get away with a PSU with it's 12V amps rated at less than that calculated above, but my sense is that we should keep an adequate margin for variability in the amp draw for a particular Ant at a particular moment in time.

==

BRAVO

mdude77

legendary

Activity: 1540

Merit: 1001

Quote from: dsheaffer on April 12, 2014, 12:16:27 AM

Jimmy,

I'm not familiar with this PSU, but perhaps the below review explains the problem. IF the below is accurate, change the OC'd S1 to one of the 45A rails and see what happens.

This review is from: SeaSonic X-1250 1250W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready
Pros: See what everyone else has said below.

Cons: It's not really a single rail, contrary to the advertising Seasonic does to this day. Both JohnnyGuru and HardOCP found that it's really a 4 rail power supply with 30/30/45/45A limits on each of the 12V rails. Before you mark my review as unhelpful, hear me out. I'm running an SLI Lightning 680 setup, where each card draws 33A (in total my rig draws around 1100W from the wall under full load). Running Furmark the overcurrent protection would kick in, and my desktop would click off.

Other Thoughts: Bottom line, Seasonic is dishonest in the specs they advertise of this psu. Yes you have to be running an insanely power hungry graphics card to find this out, but it's still wrong. I had to sell this psu at a loss and move to the Corsair AX1200i, which can handle my rig no problem because it's a real single rail design.

==

http://www.hardocp.com/article/2012/11/13/seasonic_x1250_1250w_power_supply_review/2

Read this...
"...The power information for the Seasonic X-1250 is almost identical to what we saw from the XFX ProSeries 1250W. Once more, Seasonic claims that this is a single 12v rail unit like with the Platinum-1000. However, it has been reported by 3rd parties that these units actually have four 12v rails with the layout indicated here. With the previous examples I attempted to verify this arrangement, however with the units I had to test I could not trip the OCP using the above 12v layout. As such, while the unit may indeed have four 12v rails, it seems the OCP is set such that it is unlikely it will functionally be any different than a single 12v rail power supply to users..."

You know, I don't understand the fascination with Seasonic PSUs. I've looked at the specs, and I haven't been impressed. When I see inconsistencies between their descriptions and their tech specs, and then you read about things like the above, and they are very expensive, I just don't get it.

I'm happy with my Rosewill. You guys can spend $100 more for Seasonic's if you want, but why?

M

mdude77

legendary

Activity: 1540

Merit: 1001

Quote from: dsheaffer on April 11, 2014, 11:40:08 PM

All of this discussion about the overall wattage of the PSU, line (mains) voltage, PSU efficiency, etc is driving me crazy (and it's a short ride for me). Here is how I see it.

PSUs have one or more rails that deliver +12V; the 12V rail(s) has/have a max rated amperage; the 12V rail is the only "part" of the PSU the S1 uses; therefore overall PSU "wattage" is not a limiting factor. If the Ants you connect to a PSU draw more power than the PSU's rated +12V amperage, you will shut down the PSU (best case). We can express "power" in this case as amps since we know we are always talking about a 12V system.

Bitmain says the S1 draws "360W from the wall". To give ourselves some headroom / room for error and variability, let's assume a non-overclocked S1 draws 30A (360w / 12V) from the +12V rail. If the BM statement is accurate, you will actually draw less than 30A at the 12V rail(s), but that's OK, we want a margin for error / variability in the amount of power we think the S1 draws. [Note if anyone has actually measured the amps drawn at the 12V rail, we can significantly refine our calculations]

Therefore, if you have three non-OC'd S1s on a given PSU, it better have at least a 90A rating on +12V rail. Looking at the BM chip spec and doing a little math, it appears that if an S1 is OC'd to 400MHz it will draw just over 38A. If you are connecting three S1s OC'd to 400MHz, your PSU should be rated at 115A on the 12V rail(s).

We may have built in more headroom than necessary (we essentially assumed the PSU is 100% efficient, which is clearly impossible) and you may be able to get away with a PSU with it's 12V amps rated at less than that calculated above, but my sense is that we should keep an adequate margin for variability in the amp draw for a particular Ant at a particular moment in time.

I think you're correct about all the facts. Except folks shouldn't be OC'ing to 400MHz. There are other ways to get 200GH/s out of it w/o going that high. Mine are running at 393, and running just fine at 200GH/s. According to my Kill A Watt, which doesn't lie, I'm pulling 10.65A @ 115V for 3xOC'd S1. That's 3.55A a piece @ 115V. Drop that down to 12V and you get 34A a piece. 34A * 3 = 102A on your 12V rail.

My Rosewill 1300 gold is rated at 108A on the 12V rail. That gives me 6A to spare.
My Thermaltake 1200 gold has a 85A rail, and a 40A rail. As long as I put one S1 on the 40A, and the other two other 85A, I should be able to drive 3xS1 OC'd just fine. Hopefully the 40A rail isn't on the CPU connector, cause I'm not mangling my PSU!

Thanks for pointing out the reality about the wattage. I overlooked that. That means I can use my 1200 (which right now is a backup).

EDIT: I forgot about the PSU overhead. With a gold/plat, you can assume 90%+ efficiency. So when an OC'd S1 is pulling 34A, 90% of that is the Ant (30.6) and 10% is the PSU (3.4). If you're using a 80% efficiency, you're going to be pulling 38.25A per OC'd S1.

M

freebit13

hero member

Activity: 616

Merit: 500

I got Satoshi's avatar!

Quote from: jimmyl on April 12, 2014, 02:59:35 AM

Quote from: ZiG on April 12, 2014, 12:29:18 AM

Quote from: dsheaffer on April 12, 2014, 12:16:27 AM

Jimmy,

I'm not familiar with this PSU, but perhaps the below review explains the problem. IF the below is accurate, change the OC'd S1 to one of the 45A rails and see what happens.

This review is from: SeaSonic X-1250 1250W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready
Pros: See what everyone else has said below.

Cons: It's not really a single rail, contrary to the advertising Seasonic does to this day. Both JohnnyGuru and HardOCP found that it's really a 4 rail power supply with 30/30/45/45A limits on each of the 12V rails. Before you mark my review as unhelpful, hear me out. I'm running an SLI Lightning 680 setup, where each card draws 33A (in total my rig draws around 1100W from the wall under full load). Running Furmark the overcurrent protection would kick in, and my desktop would click off.

Other Thoughts: Bottom line, Seasonic is dishonest in the specs they advertise of this psu. Yes you have to be running an insanely power hungry graphics card to find this out, but it's still wrong. I had to sell this psu at a loss and move to the Corsair AX1200i, which can handle my rig no problem because it's a real single rail design.

==

http://www.hardocp.com/article/2012/11/13/seasonic_x1250_1250w_power_supply_review/2

Read this...
"...The power information for the Seasonic X-1250 is almost identical to what we saw from the XFX ProSeries 1250W. Once more, Seasonic claims that this is a single 12v rail unit like with the Platinum-1000. However, it has been reported by 3rd parties that these units actually have four 12v rails with the layout indicated here. With the previous examples I attempted to verify this arrangement, however with the units I had to test I could not trip the OCP using the above 12v layout. As such, while the unit may indeed have four 12v rails, it seems the OCP is set such that it is unlikely it will functionally be any different than a single 12v rail power supply to users..."

Thanks, I found that when searching the internet but unsure of how to decipher.

Finally, the PCI-E are 12v1 or 12v2 or 12v3 or 12v4?
I can't find any documentation that says which PCI-E slot is 12vXX.

Looking at the charts, 12v3 & 12v4 would be your 45A supplies...

jimmyl

full member

Activity: 211

Merit: 100

Quote from: ZiG on April 12, 2014, 12:29:18 AM

Quote from: dsheaffer on April 12, 2014, 12:16:27 AM

Jimmy,

I'm not familiar with this PSU, but perhaps the below review explains the problem. IF the below is accurate, change the OC'd S1 to one of the 45A rails and see what happens.

This review is from: SeaSonic X-1250 1250W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready
Pros: See what everyone else has said below.

Cons: It's not really a single rail, contrary to the advertising Seasonic does to this day. Both JohnnyGuru and HardOCP found that it's really a 4 rail power supply with 30/30/45/45A limits on each of the 12V rails. Before you mark my review as unhelpful, hear me out. I'm running an SLI Lightning 680 setup, where each card draws 33A (in total my rig draws around 1100W from the wall under full load). Running Furmark the overcurrent protection would kick in, and my desktop would click off.

Other Thoughts: Bottom line, Seasonic is dishonest in the specs they advertise of this psu. Yes you have to be running an insanely power hungry graphics card to find this out, but it's still wrong. I had to sell this psu at a loss and move to the Corsair AX1200i, which can handle my rig no problem because it's a real single rail design.

==

http://www.hardocp.com/article/2012/11/13/seasonic_x1250_1250w_power_supply_review/2

Read this...
"...The power information for the Seasonic X-1250 is almost identical to what we saw from the XFX ProSeries 1250W. Once more, Seasonic claims that this is a single 12v rail unit like with the Platinum-1000. However, it has been reported by 3rd parties that these units actually have four 12v rails with the layout indicated here. With the previous examples I attempted to verify this arrangement, however with the units I had to test I could not trip the OCP using the above 12v layout. As such, while the unit may indeed have four 12v rails, it seems the OCP is set such that it is unlikely it will functionally be any different than a single 12v rail power supply to users..."

Thanks, I found that when searching the internet but unsure of how to decipher.

Finally, the PCI-E are 12v1 or 12v2 or 12v3 or 12v4?
I can't find any documentation that says which PCI-E slot is 12vXX.

ZiG

sr. member

Activity: 406

Merit: 250

Quote from: dsheaffer on April 12, 2014, 12:16:27 AM

Jimmy,

I'm not familiar with this PSU, but perhaps the below review explains the problem. IF the below is accurate, change the OC'd S1 to one of the 45A rails and see what happens.

This review is from: SeaSonic X-1250 1250W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready
Pros: See what everyone else has said below.

Cons: It's not really a single rail, contrary to the advertising Seasonic does to this day. Both JohnnyGuru and HardOCP found that it's really a 4 rail power supply with 30/30/45/45A limits on each of the 12V rails. Before you mark my review as unhelpful, hear me out. I'm running an SLI Lightning 680 setup, where each card draws 33A (in total my rig draws around 1100W from the wall under full load). Running Furmark the overcurrent protection would kick in, and my desktop would click off.

Other Thoughts: Bottom line, Seasonic is dishonest in the specs they advertise of this psu. Yes you have to be running an insanely power hungry graphics card to find this out, but it's still wrong. I had to sell this psu at a loss and move to the Corsair AX1200i, which can handle my rig no problem because it's a real single rail design.

==

http://www.hardocp.com/article/2012/11/13/seasonic_x1250_1250w_power_supply_review/2

Read this...
"...The power information for the Seasonic X-1250 is almost identical to what we saw from the XFX ProSeries 1250W. Once more, Seasonic claims that this is a single 12v rail unit like with the Platinum-1000. However, it has been reported by 3rd parties that these units actually have four 12v rails with the layout indicated here. With the previous examples I attempted to verify this arrangement, however with the units I had to test I could not trip the OCP using the above 12v layout. As such, while the unit may indeed have four 12v rails, it seems the OCP is set such that it is unlikely it will functionally be any different than a single 12v rail power supply to users..."

ZiG

sr. member

Activity: 406

Merit: 250

Quote from: jimmyl on April 12, 2014, 12:01:09 AM

Quote from: dsheaffer on April 11, 2014, 11:40:08 PM

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM

Quote from: dsheaffer on April 11, 2014, 11:40:08 PM

Anyone running 3 S1 on a seasonic? I need help!

I keep getting the psu going into some sort of protection mode...ie no power after running for 10 minutes.

My PCI-E are plugged into the lower right 3 PCI-E slots.

Running 2 units seems ok. PSU is 1250W, 2 units stock, 1 unit OC 375.

There probably isn't enough power on the 12V rail to run 3 S1s. Check the specs of your PSU.

I'm running 3 OC'd S1s on a Rosewill 1300 gold and pulling about 1215 watts. Mine is rated at 108A on the 12V rail. > 87% efficiency, up to 92%.

M

I have a corsair AX1200 that is running on 213V power. It is able to handle 3 antminers tuned to 387.5MHz each. (I tuned one down to 381MHz to slightly lessen the load and because that one unit was just over 1% hw errors)

I think it's the 220V that makes the difference. Based on what I'm seeing with my 1300 @ 115V, I don't see how a 1200 would cut it @ 115V.

M

All of this discussion about the overall wattage of the PSU, line (mains) voltage, PSU efficiency, etc is driving me crazy (and it's a short ride for me). Here is how I see it.

PSUs have one or more rails that deliver +12V; the 12V rail(s) has/have a max rated amperage; the 12V rail is the only "part" of the PSU the S1 uses; therefore overall PSU "wattage" is not a limiting factor. If the Ants you connect to a PSU draw more power than the PSU's rated +12V amperage, you will shut down the PSU (best case). We can express "power" in this case as amps since we know we are always talking about a 12V system.

Bitmain says the S1 draws "360W from the wall". To give ourselves some headroom / room for error and variability, let's assume a non-overclocked S1 draws 30A (360w / 12V) from the +12V rail. If the BM statement is accurate, you will actually draw less than 30A at the 12V rail(s), but that's OK, we want a margin for error / variability in the amount of power we think the S1 draws. [Note if anyone has actually measured the amps drawn at the 12V rail, we can significantly refine our calculations]

Therefore, if you have three non-OC'd S1s on a given PSU, it better have at least a 90A rating on +12V rail. Looking at the BM chip spec and doing a little math, it appears that if an S1 is OC'd to 400MHz it will draw just over 38A. If you are connecting three S1s OC'd to 400MHz, your PSU should be rated at 115A on the 12V rail(s).

We may have built in more headroom than necessary (we essentially assumed the PSU is 100% efficient, which is clearly impossible) and you may be able to get away with a PSU with it's 12V amps rated at less than that calculated above, but my sense is that we should keep an adequate margin for variability in the amp draw for a particular Ant at a particular moment in time.

==

Thanks for the detailed explanation.

That's why I cannot understand why my seasonic gold 1250 cannot handle 2 stock and 1 OC 375 ants.
2 stock should be 60 A in total.
1 OC should be less then 38A (for 400Mhz, mine is 375Mhz)
Total is only 98A.

Rating for this model is 104A.

I got a margin well over 5%. Am I missing something?

I think so...Chips Tolerance(s)...they are all DIFFERENT...I would NOT take the other's experience as MINE...Your results MAY ...and probably WILL VARY...

Mine...: I nave 5 S1's...3 are very stable @406MHz...200+ GHash...2 are "slackers"...No more than 192-199 GHash @400MHz...different heat...Temps...different power draws...Some chips are hotter than the others...on the same board(s)...I assume they consume More Amps...it is the QUALITY of the chips...Leakage current is individual for EVERY chip...

So, maybe you are running just on the edge of your Seasonic 1250...I have 3 of those...GPU farm...and they are great...but consider splitting...2 and 1/2 Ant per PSU...5 Ants on 2 Seasonics 1250... 2 x 1250 = 2500W ... / 5 Ants = 500W each (per Ant) is safe...IMHO...

Good luck..

dsheaffer

member

Activity: 98

Merit: 10

Jimmy,

I'm not familiar with this PSU, but perhaps the below review explains the problem. IF the below is accurate, change the OC'd S1 to one of the 45A rails and see what happens.

This review is from: SeaSonic X-1250 1250W ATX12V / EPS12V SLI Ready 80 PLUS GOLD Certified Full Modular Active PFC Power Supply New 4th Gen CPU Certified Haswell Ready
Pros: See what everyone else has said below.

Cons: It's not really a single rail, contrary to the advertising Seasonic does to this day. Both JohnnyGuru and HardOCP found that it's really a 4 rail power supply with 30/30/45/45A limits on each of the 12V rails. Before you mark my review as unhelpful, hear me out. I'm running an SLI Lightning 680 setup, where each card draws 33A (in total my rig draws around 1100W from the wall under full load). Running Furmark the overcurrent protection would kick in, and my desktop would click off.

Other Thoughts: Bottom line, Seasonic is dishonest in the specs they advertise of this psu. Yes you have to be running an insanely power hungry graphics card to find this out, but it's still wrong. I had to sell this psu at a loss and move to the Corsair AX1200i, which can handle my rig no problem because it's a real single rail design.

==

jimmyl

full member

Activity: 211

Merit: 100

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM

Anyone running 3 S1 on a seasonic? I need help!

I keep getting the psu going into some sort of protection mode...ie no power after running for 10 minutes.

My PCI-E are plugged into the lower right 3 PCI-E slots.

Running 2 units seems ok. PSU is 1250W, 2 units stock, 1 unit OC 375.

There probably isn't enough power on the 12V rail to run 3 S1s. Check the specs of your PSU.

I'm running 3 OC'd S1s on a Rosewill 1300 gold and pulling about 1215 watts. Mine is rated at 108A on the 12V rail. > 87% efficiency, up to 92%.

M

I have a corsair AX1200 that is running on 213V power. It is able to handle 3 antminers tuned to 387.5MHz each. (I tuned one down to 381MHz to slightly lessen the load and because that one unit was just over 1% hw errors)

I think it's the 220V that makes the difference. Based on what I'm seeing with my 1300 @ 115V, I don't see how a 1200 would cut it @ 115V.

M

All of this discussion about the overall wattage of the PSU, line (mains) voltage, PSU efficiency, etc is driving me crazy (and it's a short ride for me). Here is how I see it.

PSUs have one or more rails that deliver +12V; the 12V rail(s) has/have a max rated amperage; the 12V rail is the only "part" of the PSU the S1 uses; therefore overall PSU "wattage" is not a limiting factor. If the Ants you connect to a PSU draw more power than the PSU's rated +12V amperage, you will shut down the PSU (best case). We can express "power" in this case as amps since we know we are always talking about a 12V system.

Bitmain says the S1 draws "360W from the wall". To give ourselves some headroom / room for error and variability, let's assume a non-overclocked S1 draws 30A (360w / 12V) from the +12V rail. If the BM statement is accurate, you will actually draw less than 30A at the 12V rail(s), but that's OK, we want a margin for error / variability in the amount of power we think the S1 draws. [Note if anyone has actually measured the amps drawn at the 12V rail, we can significantly refine our calculations]

Therefore, if you have three non-OC'd S1s on a given PSU, it better have at least a 90A rating on +12V rail. Looking at the BM chip spec and doing a little math, it appears that if an S1 is OC'd to 400MHz it will draw just over 38A. If you are connecting three S1s OC'd to 400MHz, your PSU should be rated at 115A on the 12V rail(s).

We may have built in more headroom than necessary (we essentially assumed the PSU is 100% efficient, which is clearly impossible) and you may be able to get away with a PSU with it's 12V amps rated at less than that calculated above, but my sense is that we should keep an adequate margin for variability in the amp draw for a particular Ant at a particular moment in time.

==

Thanks for the detailed explanation.

That's why I cannot understand why my seasonic gold 1250 cannot handle 2 stock and 1 OC 375 ants.
2 stock should be 60 A in total.
1 OC should be less then 38A (for 400Mhz, mine is 375Mhz)
Total is only 98A.

Rating for this model is 104A.

I got a margin well over 5%. Am I missing something?

jimrome

sr. member

Activity: 434

Merit: 250

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM

Anyone running 3 S1 on a seasonic? I need help!

I keep getting the psu going into some sort of protection mode...ie no power after running for 10 minutes.

My PCI-E are plugged into the lower right 3 PCI-E slots.

Running 2 units seems ok. PSU is 1250W, 2 units stock, 1 unit OC 375.

There probably isn't enough power on the 12V rail to run 3 S1s. Check the specs of your PSU.

I'm running 3 OC'd S1s on a Rosewill 1300 gold and pulling about 1215 watts. Mine is rated at 108A on the 12V rail. > 87% efficiency, up to 92%.

M

I have a corsair AX1200 that is running on 213V power. It is able to handle 3 antminers tuned to 387.5MHz each. (I tuned one down to 381MHz to slightly lessen the load and because that one unit was just over 1% hw errors)

I think it's the 220V that makes the difference. Based on what I'm seeing with my 1300 @ 115V, I don't see how a 1200 would cut it @ 115V.

M

I ran a few ax1200i's with 3 OC'd ants (393?) each with no issues, at least in the week or so they were running. Plugs were dedicated 120V 20A CCTs at ~124V.

dsheaffer

member

Activity: 98

Merit: 10

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM

Anyone running 3 S1 on a seasonic? I need help!

I keep getting the psu going into some sort of protection mode...ie no power after running for 10 minutes.

My PCI-E are plugged into the lower right 3 PCI-E slots.

Running 2 units seems ok. PSU is 1250W, 2 units stock, 1 unit OC 375.

There probably isn't enough power on the 12V rail to run 3 S1s. Check the specs of your PSU.

I'm running 3 OC'd S1s on a Rosewill 1300 gold and pulling about 1215 watts. Mine is rated at 108A on the 12V rail. > 87% efficiency, up to 92%.

M

I have a corsair AX1200 that is running on 213V power. It is able to handle 3 antminers tuned to 387.5MHz each. (I tuned one down to 381MHz to slightly lessen the load and because that one unit was just over 1% hw errors)

I think it's the 220V that makes the difference. Based on what I'm seeing with my 1300 @ 115V, I don't see how a 1200 would cut it @ 115V.

M

All of this discussion about the overall wattage of the PSU, line (mains) voltage, PSU efficiency, etc is driving me crazy (and it's a short ride for me). Here is how I see it.

PSUs have one or more rails that deliver +12V; the 12V rail(s) has/have a max rated amperage; the 12V rail is the only "part" of the PSU the S1 uses; therefore overall PSU "wattage" is not a limiting factor. If the Ants you connect to a PSU draw more power than the PSU's rated +12V amperage, you will shut down the PSU (best case). We can express "power" in this case as amps since we know we are always talking about a 12V system.

Bitmain says the S1 draws "360W from the wall". To give ourselves some headroom / room for error and variability, let's assume a non-overclocked S1 draws 30A (360w / 12V) from the +12V rail. If the BM statement is accurate, you will actually draw less than 30A at the 12V rail(s), but that's OK, we want a margin for error / variability in the amount of power we think the S1 draws. [Note if anyone has actually measured the amps drawn at the 12V rail, we can significantly refine our calculations]

Therefore, if you have three non-OC'd S1s on a given PSU, it better have at least a 90A rating on +12V rail. Looking at the BM chip spec and doing a little math, it appears that if an S1 is OC'd to 400MHz it will draw just over 38A. If you are connecting three S1s OC'd to 400MHz, your PSU should be rated at 115A on the 12V rail(s).

We may have built in more headroom than necessary (we essentially assumed the PSU is 100% efficient, which is clearly impossible) and you may be able to get away with a PSU with it's 12V amps rated at less than that calculated above, but my sense is that we should keep an adequate margin for variability in the amp draw for a particular Ant at a particular moment in time.

==

samsonn25

hero member

Activity: 882

Merit: 1003

Quote from: klondike_bar on April 11, 2014, 08:16:06 PM