Intel vs AMD

[NINJA--]

I know intel has better processors but have you guys noticed any difference when mining? I recently switched from intel to AMD and my hash dropped significantly. I used to get a stable 350K per card and now Im getting around 320K. Ive also noticed my hash goes up and down alot more than before. It drops to 270K often and even 20K before jumping back up to 320K. Ive also noticed its takes longer to get my hash up to 320K. On intel as soon as I launch the script its as max performance in like 2 seconds. But on AMD it drags and takes longer to peak. Probably around 20 seconds. The intel rig is quad core with 4gb ram. The AMD is single core with 1 gb ram. I know mining is GPU intensive but will having cheap equipment effect my mining performance? Single core and 1 gb ram is well below what windows needs to run smoothly. Its either that or intel chips and boards are so much better it effects hash rate. What do you guys think the problem is? My first AMD rig. Im not very impressed so far.

[1713290463]

1713290463

[jake262144]

Obviously something's off as most dedicated bitcoin mining rigs are not only based on AMD processors but on the cheapest and weakest AMD cpus.

Please double-check your bios settings on that AMD mobo, mayhap some elusive power-saving option remains switched on?
You made sure Crossfire is turned off, right?

Is that a windows-based rig? Which version of Windows? Make sure Aero interface is turned off, ok?

What's the CPU usage? Idle and mining.


...or just make a clean Debian install...

[NINJA--]

I know most large scale mining rigs use cheap AMD equipment so thats why Im not sure what the problem is. I will take a look in the bios later today. I do not have CF enabled. Its not required and I hear it causes problems when mining. Im running windows 7. I have turned off all the flash visual features. I did notice a difference but the lack of performance remains. Im not sure what the cpu usage normally is I will check later. But I have noticed the system does lag. Just unzipping a zip folder shoots the cpu usage up to 100%. Im assuming dabian is a lunux based OS? I just tried ubuntu hoping for gains. The driver install is overly complicated. Theres no easy to click exe to install you have to write code just to install drivers. Same for poclbm script. When you click nothing happens gotta do more work around. I dont mind learning another OS if I will see noticeable gains but I dont want to read forums for hours just to install drivers either.

[ThiagoCMC]

Hi!

 The following AMD doc say to use some gcc options to optimize the binaries:

 http://developer.amd.com/assets/AMDGCCQuickRef.pdf

 I'm using the following options to mine my Litecoins (using cpuminer from ArtForz):

 CFLAGS = -mtune=amdfam10 -O3 -ffast-math -mabm -msse4a -pipe

 I do NOT have any Intel CPUs/hardware, because Intel send money to Israel to kill Palestinians. So, BOYCOTE ISRAEL!

 http://www.inminds.com/boycott-intel.html

Best!
Thiago

[tynt]

If CPU is too heavily loaded then GPU utilization decreases. I use GPUShark to check GPU utilization, I raise intensity until GPU is loaded 98%+.

I had the same problem if I switched from 4core to single core and underclocked CPU to 600MHz. If you raise GPU utilization to 99% then the hashrate will recover

[Flip Tulipcoin]

Hi!

 The following AMD doc say to use some gcc options to optimize the binaries:

 http://developer.amd.com/assets/AMDGCCQuickRef.pdf

 I'm using the following options to mine my Litecoins (using cpuminer from ArtForz):

 CFLAGS = -mtune=amdfam10 -O3 -ffast-math -mabm -msse4a -pipe

 I do NOT have any Intel CPUs/hardware, because Intel send money to Israel to kill Palestinians. So, BOYCOTE ISRAEL!

 http://www.inminds.com/boycott-intel.html

Best!
Thiago

FWIW, the -mabm and -msse4a flags are covered by the -amdfam10 flag, as per the document you linked. I have used the following flags with gcc 4.5.3 and many apps, for example, cgminer. Whether these flags help, hurt, or do nothing is per case, sometimes these flags have no effect at all vs a minimal set. For example -mfpmath=both can often make floating point code faster on AMD, but it can also break the ATI video drivers if used for compiling the kernel.

Big code, sometimes faster, sometimes not, sometimes broken. Works with cgminer:
-O3 -march=amdfam10 -fomit-frame-pointer -minline-stringops-dynamically -mno-align-stringops -fgcse-sm -fgcse-las -fgcse-after-reload -fweb -frename-registers -fsched2-use-superblocks -mfpmath=both -ffast-math -funroll-loops

Works with most things, often better:
-O2 -march=amdfam10 -fomit-frame-pointer -minline-stringops-dynamically -mno-align-stringops -fgcse-sm -fgcse-las -fgcse-after-reload -fweb -frename-registers -fsched2-use-superblocks

The default flags I use, I'm running Gentoo linux so the system image I use is completely compiled from scratch. These work for compiling the linux kernel, glibc, and gcc 4.5.3 itself.
-O2 -march=amdfam10 -fomit-frame-pointer -minline-all-stringops -mno-align-stringops

We probably ought to take a couple of these subjects elsewhere.

[jake262144]

But I have noticed the system does lag

Did you install the chipset drivers and the rest of the myriad of drivers bundled with your mobo?
I don't recommend you install manufacturer's utility programs but please make sure you have no missing drivers.


Yeah, Debian is a Linux distro. Ubuntu is based on Debian, in fact.

[NINJA--]

I just checked my mining rig. CPU usage is around 40%. Memory 70%. I did not see anything in bios that seems like it would affect my GPU's. Any other ideas? Im using MSI 890FXA-GD70.

[NINJA--]

I turned on GPU usage in MSI afterburner and noticed its all over the place. It frequently drops to 50-70%. Any ideas why? My intel gets a stable 99% and never drops.

[jake262144]

I can think of a few reasons why this mess could be happening.
Please start troubleshooting at 1.

[1] Overwhelmed CPU
Is this a dedicated mining rig?
A dedicated windows-based mining rig should have all the useless (in this context) housekeeping tasks turned off: no defragmentation, indexing, power saving, switching off unused hard drives, no automatic updates and by Jove don't ever use an antivirus on a dedicated miner.

That's a pretty weak CPU so if you were to use this machine as your desktop PC, the mining speed will suffer if the CPU can't keep up. Poor mining speed due to a running web browser is an ubiquitous and long-established fact of life on "mining-optimised" ( ==weak CPU ) machines.

Do you think you could monitor your CPU usage in addition to the GPU stats? CPU temps?
See what the CPU is doing when the mining speed drops happen.

[2] Faulty BIOS
You're running the most recent version, right?

[3] Motherboard too weak to provide enough juice
The MSI 890FXA-GD70 does not seem to sport the additional peripheral connector to provide more current for multiple GPU configurations.
Did you try taking one of the cards out?

[RandyFolds]

It appears you are running eight GPUs under windows...that gets my vote as the problem.

[Red Emerald]

It appears you are running eight GPUs under windows...that gets my vote as the problem.

This sounds likely.

I know cgminer creates 2 threads per GPU to help keep the activity as high as possible.  Maybe you could try that.

[RandyFolds]

I also just noticed that the usage of each GPU is perfectly matched. That is not the case in ANY of my rigs. You have some bottleneck, likely a voltage, CPU or windows issue.

What mobo has eight PCIE slots? What are you using to power eight GPUs? What extenders are you using? The PCIE bus can't handle the draw of eight cores running full blast...

[DeathAndTaxes]

It appears you are running eight GPUs under windows...that gets my vote as the problem.

There is no issue w/ running 8 GPU under Windows.  My 8 all stay right @ 99% (4x 5970s). 

[DeathAndTaxes]

I also just noticed that the usage of each GPU is perfectly matched. That is not the case in ANY of my rigs. You have some bottleneck, likely a voltage, CPU or windows issue.

What mobo has eight PCIE slots? What are you using to power eight GPUs? What extenders are you using? The PCIE bus can't handle the draw of eight cores running full blast...

Likely he is using dual GPU cards.  The perfectly matches usage may be due to Crossfire being turned on in Catalyst Control Center.  Although it shouldn't hurt mining I would turn it off.

[RandyFolds]

I also just noticed that the usage of each GPU is perfectly matched. That is not the case in ANY of my rigs. You have some bottleneck, likely a voltage, CPU or windows issue.

What mobo has eight PCIE slots? What are you using to power eight GPUs? What extenders are you using? The PCIE bus can't handle the draw of eight cores running full blast...

Likely he is using dual GPU cards.  The perfectly matches usage may be due to Crossfire being turned on in Catalyst Control Center.  Although it shouldn't hurt mining I would turn it off.

My trifired 6970s all ran differently. There is just no way their usage would match perfectly in real world conditions.

I know that eight gpus can be done in windows, I just don't think it is easy.

[NINJA--]

Dedicated mining rig with 6990. Not used for any reason except mining. No antivirus. No crossfire. I turned off the fancy display features but no other windows features. Any time I do something such as open a web browser my CPU usage shoots up to 100% and all my GPU's drop. I think its too much for the CPU. Strange cause when Im not doing anything my CPU usage is 30-40%. I did notice I have 60 processes running in the task manager. What windows services can I kill to bring the processes down? Im prolly gonna grab a dual core but would like to try to make this single core work for now.

[Red Emerald]

Dedicated mining rig with 6990. Not used for any reason except mining. No antivirus. No crossfire. I turned off the fancy display features but no other windows features. Any time I do something such as open a web browser my CPU usage shoots up to 100% and all my GPU's drop. I think its too much for the CPU. Strange cause when Im not doing anything my CPU usage is 30-40%. I did notice I have 60 processes running in the task manager. What windows services can I kill to bring the processes down? Im prolly gonna grab a dual core but would like to try to make this single core work for now.

Kill all of them and install linux. It's a dedicated mining rig so you might as well run it efficiently.

[DeathAndTaxes]

Dedicated mining rig with 6990. Not used for any reason except mining. No antivirus. No crossfire. I turned off the fancy display features but no other windows features. Any time I do something such as open a web browser my CPU usage shoots up to 100% and all my GPU's drop. I think its too much for the CPU. Strange cause when Im not doing anything my CPU usage is 30-40%. I did notice I have 60 processes running in the task manager. What windows services can I kill to bring the processes down? Im prolly gonna grab a dual core but would like to try to make this single core work for now.

Two ideas.

1) If it is a dedicated mining rig don't open a browser.  You should literally never have anything running except the miner.  Dedicated = single purpose.  Think mining appliance.  If you are browsing the web then it isn't a dedicated mining rig.

2) Linux + usb drive.  I use a single core sempron downclocked from 2.8Ghz to 1.2Ghz and rarely use more than 10% cpu w/ 3x5970 running.

[jake262144]

So, the cause seems to be your poor, overwhelmed CPU.
That constant 30% CPU usage is just Windows... that's why going Linux was among the first choices I gave you.
I already gave you some ideas as to what features you might wish to disable.

If you wish to pinpoint the source of the CPU usage more accurately, it's gonna get a tiny bit technical:
 - Install Microsoft's Sysinternals' Process Explorer ⁽¹⁾
 - Run it as root; it will show you a lot of good stuff, including CPU usage by different windows services and drivers.
 - Post a list (or a screenshot) of what's going on there, under the hood.


In my career I've seen a lot of astonishing mishaps; one cheapo laptop hogged the CPU by having its mic constantly on and doing additional postprocessing to the captured sound... the louder its environment, the more CPU was being used


Links:
(1)     http://technet.microsoft.com/en-us/sysinternals/bb896653