BF3: CPU 60%, GPUs 50% = WTF?

[Horrux]

Nope... My cousin was lagging in Starcraft II and I was looking at CPU usage and it was <20% the whole time... Once I put it in High Performance instead of Power Saver, it went up to 60~80%. This happened Friday lol

Buggy, coz that's not how it should behave. I'll try turning off CnQ & Turbo core, although I like the idea of turbo boost. Or core. Whatever.

In the meantime, I flashed the BIOS of my mobo again, and that of both 570s, updated drivers for my motherboard, etc. No DICE.

EDIT: it seems a lot of people on AMD rigs have the same problem. Someone has posted the following interesting theory about the problem, on nVidia forums:

Im having the same issue as the OP and I'm using x2 285's in sli. I would actually be able to have nice FPS if i could use both of my cards to their full potential.

There are many people having this issue however...


If the OP turns out to be using a 990fx chipset im going to throw a brick through Nvidia's window... and Dice too... for general purposes.

I think Nvidia has a 8bit switch in their drivers from the old nvidia chipset days, lol. Some of the older AMD nvidia chipsets were built with 8 bit HT buses to link to the north bridge (all modern day AMD HT implementations use 16bit). This would effectively limit ht 2.0 at the time to 2000mb/s. if using a 8 bit switch on a modern day ht 3.0 interface, that would limit the bandwidth to 4000mb/s. That is enough to saturate a PciE x16 1.x lane, however is only half as much is needed to saturate a PciE x16 2.x lane (8000mb/s). When using a AMD chipset that does not utilize the NF200 repeater chip (which are seen primarily in conjunction with Intel chipsets), both cards require full bandwidth capability when in Sli. Not to mention the latency discrepancy between PciE and the HT bus. Even if the HT bus was being utilized to its full potential, Im sure there is still little optimization within the drivers themselves for the HT bus communication to the north-bridge. So as it stands there is enough bandwidth on a AMD chipset to saturate ONE PciE Graphics cards needs, but when Sli is introduced the "Bottleneck" (as so many are anxious to refer) is in all reality in the lack of optimization to utilize the chipset's full potential. This is also why, I believe, AMD users see low GPU usage while utilizing so little CPU resources. Its the only logical explanation for the symptoms seen with AMD + Sli, and furthermore why these symptoms are not seen with the use of AMD's CrossFire.


OPTIMIZE FOR AMD CHIPSETS ALREADY!

What do you think?

 

[Horrux]

^^^
Actually, come to think of it, I don't think it can be the case, given that I had the same problem when using the hacked drivers on my unofficially supported sli mobo. The lack of performance is what got me purchasing and using a 990fx mobo instead.

 

[Horrux]

Well, I ended up replacing my phenom, mobo and RAM with a 2600k and stuff.

Works fine now, but I feel like a traitor to my beloved AMD.

 

[cadaveca]

So, did you figure out what the problem was? Just that the AMD CPU you had wasn't good enough?

 

[erocker]

Ran at stock = less than optimal IMC bandwith for a dual card system.

 

[DrunkenMafia]

I have the exact same problem on my system, I am running 2 x 5870's on a 990fx mb. I cannot get either gfx card above 60% use with crossfire on and cpu sits around 60% also. If I turn any settings on Ultra then I get drops in fps randomly down to 1fps sometimes..

I was putting it down to only having 1gb cards but there are a lot of people having this issue and most of them are on 990fx AMD rigs....

I am seriously considering jumping ship to 2600k too. I have never owned an intel rig but AMD just aren't cutting it,

 

[Horrux]

So, did you figure out what the problem was? Just that the AMD CPU you had wasn't good enough?

No, it is plenty good enough. I use to run crossfire and it ran like a champ. Now I am saddled with crappy nVidia video cards that run like malaria-induced diarrhea most of the time, and if you read this entire thread, they weren't working right on the first AM3 mobo, and not on the AM3+ mobo either.

Of course, low GPU utilization is a well known and documented nVidia bug, which they refuse to acknowledge.

Ran at stock = less than optimal IMC bandwith for a dual card system.

I OC'ed it to 3.8Ghz right before changing the mobo & CPU and it made zero difference. None whatsoever. My 1100t at 3.8 + DDR3 @ 1600 is not super-underpowered compared to a 2600k. Moreover, I still get the exact same problem in Skyrim.

I have the exact same problem on my system, I am running 2 x 5870's on a 990fx mb. I cannot get either gfx card above 60% use with crossfire on and cpu sits around 60% also. If I turn any settings on Ultra then I get drops in fps randomly down to 1fps sometimes..

I was putting it down to only having 1gb cards but there are a lot of people having this issue and most of them are on 990fx AMD rigs....

I am seriously considering jumping ship to 2600k too. I have never owned an intel rig but AMD just aren't cutting it,

That is weird, I have never, ever heard of the low GPU utilization bug applied to Radeons. The bug has nothing to do with AMD CPUs, although it might have to do with nVidia's drivers and the way they work on AMD CPUs. One can readily suspect them using an illegal, unpatched Intel compiler, for which Intel was convicted years ago of monopoly practices. See my signature for more info.

I hate Intel with a passion for all the disgusting things they have done over the years, to the consumers, to the PC market and also to their employees. I am thoroughly appalled that they are putting out by far better CPUs than AMD now, but given all the illegal advantages they have accumulated over the years, it is pretty unsurprising.

 

[bpgt64]

The "BF3 Special" 285.62

I have decided to disable SLI and I prefer how my system behaves: more constant FPS as in, less drops in the 40s and even 30s when stuff happens and no 150+fps when looking at the ground. Looks like that second $350 video card is there for nothing but aggravation.

I've always had the same problem in BFBC2 and it never got fixed. It's probably hard-coded into frostbite. :shadedshu

I know...EXACTLY what you mean. I have had twin HD 6950s(unlocked to 6970), Twin GTX 570s, a GTX 590 all within the space of the past 2 years. Where am I at now? a GTX 580 with a GT 240 for Physx/second monitor.

 

[erocker]

I OC'ed it to 3.8Ghz right before changing the mobo & CPU and it made zero difference. None whatsoever. My 1100t at 3.8 DDR3 @ 1600 is not super-underpowered compared to a 2600k. Moreover, I still get the exact same problem in Skyrim.

I'm not talking about overclocking the CPU. I'm refering to the IMC (integrated memory controller) or as the bios would list it, CPU/NB. It's an inherent weakness with Phenom II. It's allright though, you have a better chip now.

 

[cadaveca]

That is weird, I have never, ever heard of the low GPU utilization bug applied to Radeons.

You haven't been paying attention to my posts, then. I mentioned this issue with my 5870's time and again. Crazyeyesreaper reported the same problem as well. It's a lack of memory bandwidth that holds everything back.

It's so bad, that FM1 A8 3850 is better @ Codemasters titles(DiRT, F1 2010/2011) than an 1100T, even with the 1100T maxed out.

That's why erocker is making the recommendation he is...he's seen the same things too.

AMD hypes Bulldozer as being their best solution for high-resolution gaming as well, purely based on the fact that Bulldozer has a better memory controller. It's clearly not CPU power that makes Bulldozer good for high-res gaming.

 

[Horrux]

I'm not talking about overclocking the CPU. I'm refering to the IMC (integrated memory controller) or as the bios would list it, CPU/NB. It's an inherent weakness with Phenom II. It's allright though, you have a better chip now.

I didn't play with that ratio, I'll admit to that. Funny how this info comes out now that I spent $600 for hardware I am ashamed of having purchased.

 

[cadaveca]

Funny how this info comes out now that I spent $600 for hardware I am ashamed of having purchased.

It's not really anything new, though. It wouldn't fully fix the problem, either. Unfortunately, if you are running high-end GPUs(as in two, three, or four), Intel is the way to go.

It's not anyone else's fault you're ashamed for having done the right thing, either. SLi hasn't been supported on AMD CPUs, or boards, seemingly for a reason, and Crossfire isn't much better. On AMD platforms, the 69xx cards see better scaling, but even singlecard performance is better on SB and SB-E than anything AMD's got.

 

[John Doe]

Well, I ended up replacing my phenom, mobo and RAM with a 2600k and stuff.

Works fine now, but I feel like a traitor to my beloved AMD.

I heard Boy George feels that way too.

 

[Horrux]

And you know, I have my doubts because the GPUs were running at EXACTLY 50% each, most of the time... That is just too much of a coincidence.