Assessing the impact of TLB trashing on memory hard algorhitms

adaseb

legendary

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Quote from: ahsbqt on November 30, 2018, 02:45:45 PM

Old thread, but R9 390 are are doing very bad these days 26mhs thanks to tlb bug.

Yes with the R9 290 its even worse. I think I got 29MH/s with the stock clock settings on (947/1250) with Stilt bios. Now it gets less than 25MH/s and despite the speed decrease the power consumption more or less remains the same and hence its no longer profitable to mine with those GPUs.

Surprisingly they still hold a decent value for gamers and are selling on eBay for fair prices. Will most likely be putting mine up for auction soon. Highly doubt AMD will release a fix for the Hawaii chipsets.

ahsbqt

newbie

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Old thread, but R9 390 are are doing very bad these days 26mhs thanks to tlb bug.

nerdralph

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Quote from: adaseb on September 28, 2016, 06:35:40 AM

Bumping this thread...

Wondering if the RX470/RX480 will be affected by the sudden drop in hashpower when the DAG files goes to 2050MB.

Is that Dag Simulator accurate? Seems that all cards would suffer at >2GB and not just the Tahiti based cards.

AMD GCN does not have a TLB to trash. See pg. 10.
https://www.amd.com/Documents/GCN_Architecture_whitepaper.pdf

adaseb

legendary

Activity: 3808

Merit: 1723

Bumping this thread...

Wondering if the RX470/RX480 will be affected by the sudden drop in hashpower when the DAG files goes to 2050MB.

Is that Dag Simulator accurate? Seems that all cards would suffer at >2GB and not just the Tahiti based cards.

Venon

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I undervolt my 7990 to 950 mV, and the frequency is from 820 to 880 MHz, depending on the cards.

Akarabzie

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Quote from: vatusasid on March 28, 2016, 02:58:09 AM

Quote from: asrilani on March 10, 2016, 11:03:09 AM

Quote from: Akarabzie on March 10, 2016, 09:53:49 AM

Quote from: RustyNoman on March 10, 2016, 05:27:47 AM

I usually use 8 GPU in a system. 4x7990 + 4x other GPUs. AMD allow up to 8 GPU in the Windows sytem. So I use 8.

Most people don't like using the 7990s becuase they are pretty finicky and a pain to keep cool. I haven't had too much problem with mine after a pretty big underclock. I had one GPU go out on me while the other worked, and I had some problems with another one constantly crashing my system. I'd rather just run (5) 280Xs with no system downtime. Hey if you actually got 4x7990s running with no issues, more power to you. Your rig is like what 2100 watts?

I have 4x7990+4x7970. I undervolt and underclock them a lot. 950mv, 850/1500 MHz, the power is about 1330 and hah rate = 156 MH/s.

I have similar configurations. The hash rate is just 149 MH/s. So the DAG file size has reduced the hash rate by 3%.

What are you guys using to undervolt your 7990s? Just looked at mine and realized they werent actually changing from stock speeds. This may help me keep them running 24/7 since i still get the occasional crash form my 7990.

vatusasid

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Quote from: asrilani on March 10, 2016, 11:03:09 AM

Quote from: Akarabzie on March 10, 2016, 09:53:49 AM

Quote from: RustyNoman on March 10, 2016, 05:27:47 AM

I usually use 8 GPU in a system. 4x7990 + 4x other GPUs. AMD allow up to 8 GPU in the Windows sytem. So I use 8.

Most people don't like using the 7990s becuase they are pretty finicky and a pain to keep cool. I haven't had too much problem with mine after a pretty big underclock. I had one GPU go out on me while the other worked, and I had some problems with another one constantly crashing my system. I'd rather just run (5) 280Xs with no system downtime. Hey if you actually got 4x7990s running with no issues, more power to you. Your rig is like what 2100 watts?

I have 4x7990+4x7970. I undervolt and underclock them a lot. 950mv, 850/1500 MHz, the power is about 1330 and hah rate = 156 MH/s.

I have similar configurations. The hash rate is just 149 MH/s. So the DAG file size has reduced the hash rate by 3%.

asrilani

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Activity: 206

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Quote from: Akarabzie on March 10, 2016, 09:53:49 AM

Quote from: RustyNoman on March 10, 2016, 05:27:47 AM

I usually use 8 GPU in a system. 4x7990 + 4x other GPUs. AMD allow up to 8 GPU in the Windows sytem. So I use 8.

Most people don't like using the 7990s becuase they are pretty finicky and a pain to keep cool. I haven't had too much problem with mine after a pretty big underclock. I had one GPU go out on me while the other worked, and I had some problems with another one constantly crashing my system. I'd rather just run (5) 280Xs with no system downtime. Hey if you actually got 4x7990s running with no issues, more power to you. Your rig is like what 2100 watts?

I have 4x7990+4x7970. I undervolt and underclock them a lot. 950mv, 850/1500 MHz, the power is about 1330 and hah rate = 156 MH/s.

Akarabzie

full member

Activity: 146

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Quote from: RustyNoman on March 10, 2016, 05:27:47 AM

I usually use 8 GPU in a system. 4x7990 + 4x other GPUs. AMD allow up to 8 GPU in the Windows sytem. So I use 8.

Most people don't like using the 7990s becuase they are pretty finicky and a pain to keep cool. I haven't had too much problem with mine after a pretty big underclock. I had one GPU go out on me while the other worked, and I had some problems with another one constantly crashing my system. I'd rather just run (5) 280Xs with no system downtime. Hey if you actually got 4x7990s running with no issues, more power to you. Your rig is like what 2100 watts?

RustyNoman

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I usually use 8 GPU in a system. 4x7990 + 4x other GPUs. AMD allow up to 8 GPU in the Windows sytem. So I use 8.

Satlite

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Quote from: sp_ on February 25, 2016, 08:53:10 AM

Quote from: apriyoni on February 25, 2016, 07:55:14 AM

Quote from: sp_ on February 25, 2016, 05:07:50 AM

Quote from: Realetim on February 25, 2016, 04:51:42 AM

Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).
The best card for mining etherum is the r9 Nano. It does 28MHASH.

Does the R9 nano use more electricity? Which is more efficient in terms of hash per watt? Nano or 970?

The NANO use less electricity, but cost more.

The R9 nano costs £388 while the 970 costs £250. So there is £138 or $200 difference. that is quite a lot.

33% faster and 55% more expensive, but it draws less power..

In percentage term, it could be a good deal if you can squeeze 6 GPU and reduce the overhead of the system.

adaseb

legendary

Activity: 3808

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You guys are all wrong the best card to mine is probably the 7950/7970 since its can be bought second hand dirt cheap. And it gets 20Mh/s.

Buying the Nano or Fury? What are the chances that ETH will still be profitable the day you get ROI ?

rednoW

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Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).

The best card for mining etherum is the r9 Nano. It does 28MHASH.

nope, the best card for eth is 390x now, fury is good for decred

sp_

legendary

Activity: 2926

Merit: 1087

Team Black developer

Quote from: apriyoni on February 25, 2016, 07:55:14 AM

Quote from: sp_ on February 25, 2016, 05:07:50 AM

Quote from: Realetim on February 25, 2016, 04:51:42 AM

Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).
The best card for mining etherum is the r9 Nano. It does 28MHASH.

Does the R9 nano use more electricity? Which is more efficient in terms of hash per watt? Nano or 970?

The NANO use less electricity, but cost more.

The R9 nano costs £388 while the 970 costs £250. So there is £138 or $200 difference. that is quite a lot.

33% faster and 55% more expensive, but it draws less power..

apriyoni

sr. member

Activity: 308

Merit: 250

Quote from: sp_ on February 25, 2016, 05:07:50 AM

Quote from: Realetim on February 25, 2016, 04:51:42 AM

Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).
The best card for mining etherum is the r9 Nano. It does 28MHASH.

Does the R9 nano use more electricity? Which is more efficient in terms of hash per watt? Nano or 970?

The NANO use less electricity, but cost more.

The R9 nano costs £388 while the 970 costs £250. So there is £138 or $200 difference. that is quite a lot.

sp_

legendary

Activity: 2926

Merit: 1087

Team Black developer

Quote from: Realetim on February 25, 2016, 04:51:42 AM

Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).
The best card for mining etherum is the r9 Nano. It does 28MHASH.

Does the R9 nano use more electricity? Which is more efficient in terms of hash per watt? Nano or 970?

The NANO use less electricity, but cost more.

Realetim

newbie

Activity: 30

Merit: 0

Quote from: sp_ on February 25, 2016, 04:27:14 AM

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).

The best card for mining etherum is the r9 Nano. It does 28MHASH.

Does the R9 nano use more electricity? Which is more efficient in terms of hash per watt? Nano or 970?

sp_

legendary

Activity: 2926

Merit: 1087

Team Black developer

You can get the gtx 970 to 21 MHASH by putting the gtx 970 in P1 mode. (nvidia-smi tool).

The best card for mining etherum is the r9 Nano. It does 28MHASH.

Genoil

sr. member

Activity: 438

Merit: 250

Quote from: adaseb on February 25, 2016, 04:11:11 AM

Quote from: Genoil on February 25, 2016, 03:53:33 AM

Quote from: adaseb on February 25, 2016, 03:33:27 AM

So we are currently at 1280MB for the DAG file size and most people are still mining. Was the bug fixed?

It turned out the big bug wasn't really there. My (false) assumptions were based on reports by testers of dagSimCL who apparently didn't know how to tune their AMD cards correctly.

The impact of DAG size on hashrate is a fact though. While on Nvidia it has the most dramatic effects in certain circumstances, the impact on AMD cards has been growing steadily now to such a level that the 280X is now dethroned as most cost-effective card to mine on, losing its position to GTX970 on Win7/Linux.

I noticed the decrease in speed also.

The 970 however seems to be at least double in price compared to the 280X.

Yes it only counts when you have already ROI'd on the cards mining other coins

adaseb

legendary

Activity: 3808

Merit: 1723

Quote from: Genoil on February 25, 2016, 03:53:33 AM

Quote from: adaseb on February 25, 2016, 03:33:27 AM

So we are currently at 1280MB for the DAG file size and most people are still mining. Was the bug fixed?

It turned out the big bug wasn't really there. My (false) assumptions were based on reports by testers of dagSimCL who apparently didn't know how to tune their AMD cards correctly.

The impact of DAG size on hashrate is a fact though. While on Nvidia it has the most dramatic effects in certain circumstances, the impact on AMD cards has been growing steadily now to such a level that the 280X is now dethroned as most cost-effective card to mine on, losing its position to GTX970 on Win7/Linux.

I noticed the decrease in speed also.

The 970 however seems to be at least double in price compared to the 280X.

Topic: Assessing the impact of TLB trashing on memory hard algorhitms (Read 7714 times)