x1 to x16 risers... a basic question

feofhweufheuiwhfef

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Quote from: Starscream on March 04, 2014, 05:20:17 AM

Quote from: feofhweufheuiwhfef on March 04, 2014, 05:16:29 AM

I presume that the overall power usage would be 30-40 watts x 3, which is 90-120 watts.

Would that really be too much for the motherboard to handle?

Thanks

If that's the case, than no, it wouldn't be to much for the motherboard to handle and you can safely skip powered risers. I was thinking you'd wanna buy a lot more cards thus said with quite certainty that you'd need powered risers.

Do you have any sort of guide as to what is considered "too much" for the motherboard..?

Is it 75 watts per x1 and x16 slot, or is it something else entirely?

I know that AMD RADEON cards are 100 watts+, and so, I assume this is why they need 6-pin connectors, because x16 slots have 75 watts.

Is this correct? What is the amount of watts that x1 and x16 slots support, and does it change for PCIe 2.0, 3.0 etc?

Thanks

Starscream

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Quote from: feofhweufheuiwhfef on March 04, 2014, 05:16:29 AM

I presume that the overall power usage would be 30-40 watts x 3, which is 90-120 watts.

Would that really be too much for the motherboard to handle?

Thanks

If that's the case, than no, it wouldn't be to much for the motherboard to handle and you can safely skip powered risers. I was thinking you'd wanna buy a lot more cards thus said with quite certainty that you'd need powered risers.

feofhweufheuiwhfef

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Quote from: Starscream on March 03, 2014, 09:12:07 PM

Quote from: feofhweufheuiwhfef on March 03, 2014, 08:41:01 PM

Quote from: Starscream on March 03, 2014, 08:11:13 PM

1. Yes, but you should get powered risers if you plan to have lots of cards.
2. It won't reduce any KH/s
3. There's no issue to begin with (see #2)
4. They are plugged via a normal power cable to your PSU (usually a molex connector, although there are sata ones too).

Thanks

but if (2) and (3) are not an issue, then why would I want to get powered risers?

Because you don't want all the extra power to go through your motherboard. It's the same reason anyone who uses multiple of any type of card (nVidia or AMD) uses powered risers.

Most motherboards are designed to handle maximum 2 additional cards boarded on them, which equates to additional 150w (+/-). More cards (75w+- per card) means more power is needed to power them - more current goes through the motherboard, which means increase in likelihood of frying said motherboard.

OK... but here's one interesting thing about the nVidia 750 Ti

According to this blog post, they only use between 30 and 40 watts.

So my question is, are they going to use 75 watts just because that's what the x16 slot is, or will they in fact use 75 watts anyway?

I mean, here is what I was planning

1x 750 Ti in the x16 slot
2x 750 Ti in the x1 slot, with riser cable

I presume that the overall power usage would be 30-40 watts x 3, which is 90-120 watts.

Would that really be too much for the motherboard to handle?

Thanks

kalus

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let's make a deal.

Quote from: WireIT on March 04, 2014, 12:11:55 AM

I have heard the ribbon style risers, like the ones you linked to, usually do not last as well as the USB versions. The flat ribbon cables can either brake or the soldered connections can separate from pressure of bending and/or moving the cables around. The USB option is more flexible and should last longer. Just make sure you find powered ones, ideally with caps on the board to help stabilize the power.

if you're mining, you shouldn't be futzing with the hardware. is your mining rig attached to a kangaroo or something?

WireIT

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I have heard the ribbon style risers, like the ones you linked to, usually do not last as well as the USB versions. The flat ribbon cables can either brake or the soldered connections can separate from pressure of bending and/or moving the cables around. The USB option is more flexible and should last longer. Just make sure you find powered ones, ideally with caps on the board to help stabilize the power.

relm9

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Quote from: atp1916 on March 03, 2014, 09:09:13 PM

Do not put more than 2 powered risers on the 5v lines (molex).

I thought powered risers pull from 12V. Correct me if I'm wrong? Don't see how people are putting 5 or more on these on risers if what you say is true. I've only ever used risers with cards that are powered from the PSU though.

everything_zen

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Quote from: feofhweufheuiwhfef on March 03, 2014, 08:41:01 PM

Quote from: Starscream on March 03, 2014, 08:11:13 PM

1. Yes, but you should get powered risers if you plan to have lots of cards.
2. It won't reduce any KH/s
3. There's no issue to begin with (see #2)
4. They are plugged via a normal power cable to your PSU (usually a molex connector, although there are sata ones too).

Thanks

but if (2) and (3) are not an issue, then why would I want to get powered risers?

Risers are just required for fitting many cards on one motherboard, and then the mobo has difficulty supplying power to numerous cards so you need powered risers.

Starscream

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Activity: 364

Merit: 250

Quote from: feofhweufheuiwhfef on March 03, 2014, 08:41:01 PM

Quote from: Starscream on March 03, 2014, 08:11:13 PM

1. Yes, but you should get powered risers if you plan to have lots of cards.
2. It won't reduce any KH/s
3. There's no issue to begin with (see #2)
4. They are plugged via a normal power cable to your PSU (usually a molex connector, although there are sata ones too).

Thanks

but if (2) and (3) are not an issue, then why would I want to get powered risers?

Because you don't want all the extra power to go through your motherboard. It's the same reason anyone who uses multiple of any type of card (nVidia or AMD) uses powered risers.

Most motherboards are designed to handle maximum 2 additional cards boarded on them, which equates to additional 150w (+/-). More cards (75w+- per card) means more power is needed to power them - more current goes through the motherboard, which means increase in likelihood of frying said motherboard.

atp1916

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Do not put more than 2 powered risers on the 5v lines (molex).

feofhweufheuiwhfef

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Activity: 25

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Quote from: Starscream on March 03, 2014, 08:11:13 PM

1. Yes, but you should get powered risers if you plan to have lots of cards.
2. It won't reduce any KH/s
3. There's no issue to begin with (see #2)
4. They are plugged via a normal power cable to your PSU (usually a molex connector, although there are sata ones too).

Thanks

but if (2) and (3) are not an issue, then why would I want to get powered risers?

Starscream

sr. member

Activity: 364

Merit: 250

1. Yes, but you should get powered risers if you plan to have lots of cards.
2. It won't reduce any KH/s
3. There's no issue to begin with (see #2)
4. They are plugged via a normal power cable to your PSU (usually a molex connector, although there are sata ones too).

feofhweufheuiwhfef

newbie

Activity: 25

Merit: 0

I am planning to use nVidia 750 Ti cards in my rig, which don't actually require any power other than that from the PCI-E slot.

I would like to ask, how do risers work?

I have seen the followng on ebay:

http://www.ebay.co.uk/itm/PCI-E-Express-x1-to-x16-Adapter-Extender-Cable-Riser-Card-Mining-Cooling-bitcoin-/251461244051?_trksid=p2054897.l4275

for only £6.99, you get a 26 cm x1 to x16 riser cable....

Here are my questions

1. Will this work wth my 750 Ti

2. How much Khash will this reduce from my 750 Ti, if any? It is said to do 273 Khashes on its default settings, with no overclocking etc

3. If I got a powered riser, would this remove any issues with reducing the Khashes

4. How do powered risers work? Are they powered by USB, or are they powered by 6-pin or 4-pin PSU connectors, or what?

Thanks

Topic: x1 to x16 risers... a basic question (Read 693 times)