Topic: Intel vs AMD (Read 8998 times)

Typically in Linux you do not install drivers; they are part of the kernel, so you already have them. Exceptions include proprietary video drivers; AMD catalyst is  already installed in linuxcoin, and its the version you want for mining. Nothing extra needed. Ubuntu comes with opensource drivers, and for mining you need proprietary ones, which you install with the "Additional Driver" application and it takes like 2 clicks. Do not use the newest versions of ubuntu though, since they come with more recent AMD drivers which are crappy for mining. In fact, do not use ubuntu for mining. You can run ubuntu from a stick, but only with the open drivers. To run ubuntu with the proprietary drivers from a stick is possible, but not so easy to achieve.

Powersaving mode on your cpu is just fine. Your northbridge determines the number of PCIE lanes and by consequence all PCIE traffic (along with cpu) passes through it as far as I understand. If this is bottlenecking it would slow down GPU's simultaneously as was observed along with the CPU. Most people would not run into problems saturating the PCIE lanes on a motherboard but I can see 4x6990 causing some problems on a dated chipset.

No, it's a Phenom II. I just mean that there's nothing bad in powersaving mode, because it doesn't (and shouldn't) affect gpu performance.

If your cpu is not needed then cool and quiet should underclock it to reduce power consumption. As long as it speeds up when you go to use it for something else you are not doing anything wrong. With such low clock speeds are you running bulldozer?

My cpu is currently working @ 783 mhz - same mhash/s as with 3 ghz and ZERO cpu usage. I'm doing something wrong?

Check the aggression in the miner. This type of drop is common if my aggression is set to 5. With my aggression set to 13 it stays 99% 100% of the time. If you are mining with the same settings on all this is one possible explanation I can think of. I am not running multiple GPU's but if the aggression is not the case then something is bottlenecking. I suggest you also check your chipset temperature on your motherboard. If it is overheating it might be slowing down the cards to protect itself. I had this issue with my CPU on the 790 chipset. Now I am on the 990FX chipset and have never had it slow anything down. Usually if your chipset goes into autoprotect mode it will slow down your CPU so keep an eye to see if your clock speeds are consistent.

 There's no difference between energy saving on/off because there's no cpu usage at all and should'nt be, if it's not a cpu bug with AMD APP SDK 2.5. And looks like you have it. Just use SDK 2.4.

Is their some kinda energy saving mode being turned on/off since it looks like that is happening
Amd cpu tend to go very low in energy save which can be a pain in the ass, when you turn it off and see what happens.
And yes it happens on intel cpu's as well but since the difference is smaller on intel between the steps it has a less annoying effect

Dont be so anal. This is a dedicated miner. I was watching the CPU usage while doing basic things to troubleshoot.



Im thinking about trying linux. I hear you get 10% increase hash over windows. Plus booting off USB instead of a HD is pretty sweet. And if your telling me it also uses less CPU than windows it sounds like a dream come true. Like I said I did try ubuntu it was amazing to install but installing drivers was a nightmare. How do you install drivers on linux? Is it nice and simple like windows just click exe or is it a pain in the ass?

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

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.

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

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.

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.

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.

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

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...

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.

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

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?

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.

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.

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.

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.

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

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

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.

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...

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.