Cheap Sandy Bridge-EP Xeons

[Slowlemon]

Hi All

I have spent most of this weekend experimenting with this system to try and understand the CPU throttling issue. So far it appears that everything is working perfectly. The CPU frequency scaling feature in Linux is working as it should do and does not seem to be limiting performance. The Intel turbo boost is working and the CPUs are throttling to stay within their design parameters.

The difference between the two chips could simply be due to variations in manufacture. One is running at about 2220MHz and the other at about 2340MHz. I have been running with the slow CPU in socket 0 and the fast CPU in socket 1. I tried swapping the processors round to see if that has any effect but the system will not post with the faster CPU in socket 0. I think building a multi-socket computer using ES chips from Ebay is not straightforward .

It looks like the only way I am going to get more speed is to overclock the base clock.

Wish me luck.

[kirk46]

good luck

[Ben Lamb]

Originally Posted by Slowlemon

Hi All

I have spent most of this weekend experimenting with this system to try and understand the CPU throttling issue. So far it appears that everything is working perfectly. The CPU frequency scaling feature in Linux is working as it should do and does not seem to be limiting performance. The Intel turbo boost is working and the CPUs are throttling to stay within their design parameters.

The difference between the two chips could simply be due to variations in manufacture. One is running at about 2220MHz and the other at about 3340MHz. I have been running with the slow CPU in socket 0 and the fast CPU in socket 1. I tried swapping the processors round to see if that has any effect but the system will not post with the faster CPU in socket 0. I think building a multi-socket computer using ES chips from Ebay is not straightforward .

It looks like the only way I am going to get more speed is to overclock the base clock.

Wish me luck.

3340mhz !!!!!!! please tell me that was a typo and you mean 2340mhz.

I have done everything I can to get mine running faster and nothing works.

cpuinfo says the cpus are running at 2080mhz no matter what I do, I am hoping that it does not register turbo speeds.

I have given up on it now as it was making me mad but no sign of these supposed 2.8ghz clocks.

I recon it could be running at 2080mhz which is poop but these xeons must be awefully fast to produce decent ppd at this low speed.

[Slowlemon]

Hi Ben

Yes that`s a typo, should be 2340MHz . CPUinfo will not show turbo speed, it shows base clock times base multiplier (104 x 20 = 2080MHz). I have been able to get my base clock up to 104MHz same as yours. When I try 105 it locks up and refuses to POST (code 34 something to do with memory).

I tried increasing VSA to 1.100v but it made no difference so I have chickened out and left it at 104. I thought that the CPUs would throttle back to compensate for the increased base clock but they don`t, both processors have increased by 4% so they are now running at 2309MHz and 2434MHz. That will have to do until I can come up with something better.

[Slowlemon]

Hi All

The dual Xeon rig is back on Bigadv after I spent all weekend tweaking it to try and get more performance. With the 4% overclock TPF on P8101 has come down to 21m, 20s for about 176K PPD, an increase of 14K. Power consumption is up 5W to 245W, efficiency has gone up to 718PPD/W .

I am very pleased with the performance of this system for the money spent. It was a big risk to order ES chips from an Ebay seller on the other side of the world and It has been an eventful build, but the results are so worth it . I can`t wait to see how Coolamasta gets on with his.

[Ben Lamb]

Originally Posted by Slowlemon

Hi All

The dual Xeon rig is back on Bigadv after I spent all weekend tweaking it to try and get more performance. With the 4% overclock TPF on P8101 has come down to 21m, 20s for about 176K PPD, an increase of 14K. Power consumption is up 5W to 245W, efficiency has gone up to 718PPD/W .

I am very pleased with the performance of this system for the money spent. It was a big risk to order ES chips from an Ebay seller on the other side of the world and It has been an eventful build, but the results are so worth it . I can`t wait to see how Coolamasta gets on with his.

This is the final straw my tpf is 24min 10s I have stopped my machine in the middle of an 8101 and am installing ubuntu instead of the old fahlinux 1.3.4 which I recon is well out of date. I have even installed graphics now - I will get to the bottom of this - cant stand these low tpf anymore !

[Ben Lamb]

Originally Posted by Ben Lamb

This is the final straw my tpf is 24min 10s I have stopped my machine in the middle of an 8101 and am installing ubuntu instead of the old fahlinux 1.3.4 which I recon is well out of date. I have even installed graphics now - I will get to the bottom of this - cant stand these low tpf anymore !

Ok Ubuntu 12.04 installed and running, kraken installed - going to run off a few smp units for a day then switch back to bigadv. Have i7z and the cpus are running at 2350 so similar to yours will be interesting to see if my tpf is fixed now.

[Ben Lamb]

Originally Posted by Ben Lamb

Ok Ubuntu 12.04 installed and running, kraken installed - going to run off a few smp units for a day then switch back to bigadv. Have i7z and the cpus are running at 2350 so similar to yours will be interesting to see if my tpf is fixed now.

Ok think I have got to the bottom of this now - my tpf has improved slightly to 23m 50s v7 says 21m 10s but that is bull if you work out the tpf from the log tab it is way higher.

All that longterm power limt stuff in the asus bios is useless as you only get the boost for 32 seconds as that is the max the bios allows then it throttles down from 24x to 22x. There will be a hack to sort this - google throttlestop which is an app you can use in windows to stop throttling and lock turbo multis. We need to do this in linux, the asus board is a bit of a waste of time as the only overclocking we have is 4mhz on the blck.

[Slowlemon]

Originally Posted by Ben Lamb

Ok Ubuntu 12.04 installed and running, kraken installed - going to run off a few smp units for a day then switch back to bigadv. Have i7z and the cpus are running at 2350 so similar to yours will be interesting to see if my tpf is fixed now.

Hi Ben

Your hardware is virtually identical to mine so I think it must be a software issue or possibly firmware. I am using BIOS 0703 but I doubt that will make any difference. I posted some of the settings I am using in Coolamastas thread (post 13) everything else is on default and or auto.

Did you install the 64 bit version of Ubuntu? The version I have is ubuntu-12.04-desktop-amd64. Did you install the latest version of Thekraken? 0.7-pre15. Do you have NUMA and ACPI enabled in the BIOS?

[Ben Lamb]

Originally Posted by Slowlemon

Hi Ben

Your hardware is virtually identical to mine so I think it must be a software issue or possibly firmware. I am using BIOS 0703 but I doubt that will make any difference. I posted some of the settings I am using in Coolamastas thread (post 13) everything else is on default and or auto.

Did you install the 64 bit version of Ubuntu? The version I have is ubuntu-12.04-desktop-amd64. Did you install the latest version of Thekraken? 0.7-pre15. Do you have NUMA and ACPI enabled in the BIOS?

It is working well now TPF has settled at 21min 30s which is great. The latest version of thekraken is excellent and is what is making the difference here. These chips are great, the fast 3.6ghz ones could hit 15min tpf and have got to be the best choice for folding. If there was an unlocked chip performance would be amazing.

[Slowlemon]

Originally Posted by Ben Lamb

It is working well now TPF has settled at 21min 30s which is great. The latest version of thekraken is excellent and is what is making the difference here. These chips are great, the fast 3.6ghz ones could hit 15min tpf and have got to be the best choice for folding. If there was an unlocked chip performance would be amazing.

Hi Ben

I`m glad you got it sorted. I am sure Thekraken is a big advantage, maybe that`s what is missing from the Linux folding image? Or is it an older version? If you can pin down the problem then it will help other team members update their systems.

[Ben Lamb]

Originally Posted by Slowlemon

Hi Ben

I`m glad you got it sorted. I am sure Thekraken is a big advantage, maybe that`s what is missing from the Linux folding image? Or is it an older version? If you can pin down the problem then it will help other team members update their systems.

Turned out that the older image used a kernel that didn't seem to make use of turbo boost so cores were stuck at the base speed. 12.04 enables turbo so it is faster.

[Slowlemon]

Originally Posted by Ben Lamb

Turned out that the older image used a kernel that didn't seem to make use of turbo boost so cores were stuck at the base speed. 12.04 enables turbo so it is faster.

Thanks Ben. So it looks like people running newer hardware like Intel Sandy Bridge or AMD Bulldozer based CPUs should be using Linux with an up to date kernel. This is perfectly logical but I bet lots of people are using an older kernel because they "think" it`s faster.