• Competitor rules

    Please remember that any mention of competitors, hinting at competitors or offering to provide details of competitors will result in an account suspension. The full rules can be found under the 'Terms and Rules' link in the bottom right corner of your screen. Just don't mention competitors in any way, shape or form and you'll be OK.

CPU Bottleneck

sparx1981

sparx1981

sparx1981

Associate
Joined
9 May 2011
Posts
38
Hi guys and girls,

I'm currently running an i7 870 (Oc'd @ 3.52ghz) (1156 chipset) with 8gb of Ram, 6990 + 6970 in trifire.
I can get most things running at full settings and gaming at 6256 x 1152. I do think that my CPU is causing a bottleneck though.

Does anyone have any suggestion on ways to ease this problem without upgrading or alternatively... if I did have to upgrade, what chip would be best?

Sadly money is a barrier so I dont want to go up to a new 3930k chip... although that would be nice.

I've also taken a look at 2500k and 2600k chips... these are newer but I wonder if they are much different in performance compared to my i7 870.
 
Firstly you haven't really described the issues you are having so its not possible to advise you any further fella.

Secondly your sig is too big as only 4 lines of text are allowed :D

What I will add though is that there is no way your CPU is causing a bottleneck imo.
 
I can get most games to play at 6256 x 1152 and the highest settings. Battlefield runs ok but maybe a little slow. If I play Crysis 2, only two GPU's get utilised but I think thats down to the game rather than my machine.

Batman Arkham City however has 50% utilisation on each GPU. My CPU usage does spike highly though. All I get at the moment while playing this is between 10 and 20 fps on max settings. Looking at the forums though I know this game has problems with Direct X 11 at the moment though.... I dont know if a new CPU will boost performance in these games or not though? I know the i7 870 is a little old now.
 
Really? You think it's the GPU's causing the issue? I use the widescreengamingforum as a point of reference and I dont think this should be a problem.
 
It might be worth noting that my RAM is running in single channel single channel mode. unfortunately 1156 chipsets only allow single channel when running 1600mhz ram. The below link goes directly to the manual for my motherboard.

http://support.asus.com/download/download_item_mkt.aspx?slanguage=en-us&model=P7P55D-E+PRO

On page 2-11 it states "Due to Intel Spec definition X.M.P DIMMS and DDR3-1600 are supported for one DIMM per channel only"


Would this make a massive impact on performance? If so how can I get around it? when I try to run this memory in dual channel it detects 8gb but in windows it says that only 4gb is usable.
 
I guess if this does make an impact an alternative would be to drop to 1333mhz ram and run this in Dual channel. But would this make any difference considering the drop in speed?
 
can you benchmark at your gaming resolution?
if you can run a benchmark with your CPU as your opening post states ie: 3.52 Ghz, downclock by 200Mhz and try again and finally clock it further by 200 Mhz (i see you used to have it at 4GHz according to your sig) post back with the results and we can then see whats happening.
 
sparx1981 said:
It might be worth noting that my RAM is running in single channel single channel mode. unfortunately 1156 chipsets only allow single channel when running 1600mhz ram.
Click to expand...

Erm thats not accurate. See my S1156 rig below.

cpu-z.jpg
 
I can do some proper benchmarking tomorrow, I think it may take a little while to do the adjustments and re-runs. What bench mark would you like me to use? Ungine? PC Mark? 3D Mark?
 
Hi ManCuBus,

I agree with your CPU-Z findings. I used to have a MSI motherboard which was 1156. This did let me run these as Dual channel. I changed to an ASUS board because the MSI one had poor performance for SSD drives. They were only running at half their speed. The ASUS one has a special PCI bridge that allows these and USB 3.0 to work at their full speed.

Since solving that one problem it appears I've found that this board only allows single channel 1600mhz RAM.

I'm currently running 4gb x 2 @ 1600mhz. These are in slots B1 and B2 on an Asus P7P55De-Pro. With these in B1 and B2 these work in single channel opperation.

For dual channel opperation they should be in B1 and A1. When I do this though it detects the RAM however in Windows it only shows as 8gb (4gb usable).

I have tried to downclock the RAM below 1600mhz to see if this allows it to be used in dual channel however I have not had any luck with this. I still get the 8gb (4gb usable)
 
morning guys,

Ok, I've tried getting the ram to work in dual channel again and managed to get it working if I up the voltage to 1.65v. I did have to press the mem ok button to start with but hopefully this was a one off.

So... in short I now have 8GB of Ram in Dual Channel mode.

Sadly this made no difference to my gaming speeds and therefore my orginal question.

I've re-run a test on Arkham City and all three GPU's are using 50%. My CPU doesn't seem to be at 100% either though. Is this a CPU bottleneck or something else (AKA bad programming) causing the game not to use all available resource.
 
Could it be the issue of running tri-fire and PCI-E bandwidth on socket 1156 board?

Cause usually when you crossfire on 1156 board, it'll be running crossfire at x8/x8; but since 6990 is already running internal crossfire at x8, and when you go trifire, the 6990 would probably be like running crossfire on top of another crossfire. I'm not entirely certain, but while running the 6990 on its own on the first PCI-E x16 would be fine, by adding a 6950 to crossfire with the 6990 would drop the 1st PCI-E x16 slot's bidwidth by half, so in theory it would be like the two GPUs in the 6990 would be running at like x4/x4 speed, and the 6970 probably also drop to x4 to match the two GPUs in the 6990 may be?

Actually, have you tried running the 6990 on its own, and see if it is actually deliver better performance than your trifire set up?
 
Just re-done the test with and without crossfire enabled. I get the same FPS basically. So the addition of the 6970 does pretty much nothing in this game. Any ideas?
 
Looking at the 2600k vs i7 870 there isn't a huge leap in performance. The 3930 isn't vast either however it does have 2 extra cores... that said the cost of the new chip and board seem a lot considering the difference they'd make.

Any thoughts?
 
To clarify this a bit more, Battlefield 3, ultra settings at 6256 x 1152... 40 fps. I'm happy with that. But Arkham City, Metro 2033 and Crysis 2 at max settings get around 15 fps.
 
You must log in or register to reply here.
Back
Top Bottom