Okay guys, im at my wit's end with this, and i have tried googling, and lurking several forums to get a solution, to little avail. the problem is somewhat complex, but ill give you the run down. i bought a new rig sometime last year, however encountered that i had issues with a 7870 (1 of 2) in my rig, RMAed it and get a replacement, however in the mean time i decided to upgrade to the ATI 280x, but didnt get very good performace, i took the cards back and replaced them with 2 EVGA GTX 770 superclocked.
now the main reason for this is that i run a 4 monitor setup ( 3 identical screens and a TV) so 2 cards is generally preferable, and i wanted some real horsepower for BF4 and other future titles. in BF4 i noticed that SLI was barely improving my FPS at all, and that i was getting a lot of microstuttering, i tested out 3d mark 11 and SLi did improve my performace, so all was dandy, but i wanted to optimise for BF4. after a few tweaks SLi began to decrease performance in BF4, so i did a fresh windows install and upgraded to 8.1.
after the reinstall i have the same problems, SLi seems to lower my FPS and gives me major microstuttering in BF4, i checked the perfoverlay.drawgraph and saw that in SLI mode i was getting massive CPU spikes that coincided with the stuttering effect. with SLi off and K-BOOST enabled i get about 85-140 FPS on ultra, but with SLI, i get anywhere from 40-85 FPS.
i tried both cards in both slots on my mobo, and both of them run just fine individually, so i know its not a faulty GPU, but im new to nvidia, so im not sure about drivers. i have updated my BIOS and that has increased single GPU perfomance marginally, but no difference in SLi. figuring that it may just be BF4 i tried Heaven Benchmark 4.0 and got similar results, barely an FPS improvement, much lower min FPS and stuttering everywhere. exactly the same problem in 3DMARK vantage, with a score of 23830 SLi OFF and 24644 with SLi ON.
graphics scores are 25444.1 with SLi off and 26606.1 with SLi on, and the cpu scores are similar but slightly higher with SLi on.
here are my system specs :
windows 8.1
Asus Crosshair V Formula-z motherboard
AMD FX-8350 running at 4.3GHz with a Corsair H100i
16gb Corsair vengeance RAM @ 1633 or so
2 x EVGA GTX 770 SC
256gb OCZ vertex SSD
3-4TB of other HDD space
Corsair AX860i PSU (plenty of juice to power the cards)
i have tried setting my CPU to stock speeds, but no difference as the OC is pretty low anyway. I'm at a loss for what is causing this, i'm thinking there may be a motherboard issue as this isn't the first time i have had multiple GPU performance issues, and both cards are completely fine. the original 7870's did have a legit problem, but im thinking the low performance on the 280x's may have been down to something else.
thanks for any help you can give guys, i really want to stretch the legs of this machine and its disappointing to waste the potential of an extra 770 that cost a lot of money.
now the main reason for this is that i run a 4 monitor setup ( 3 identical screens and a TV) so 2 cards is generally preferable, and i wanted some real horsepower for BF4 and other future titles. in BF4 i noticed that SLI was barely improving my FPS at all, and that i was getting a lot of microstuttering, i tested out 3d mark 11 and SLi did improve my performace, so all was dandy, but i wanted to optimise for BF4. after a few tweaks SLi began to decrease performance in BF4, so i did a fresh windows install and upgraded to 8.1.
after the reinstall i have the same problems, SLi seems to lower my FPS and gives me major microstuttering in BF4, i checked the perfoverlay.drawgraph and saw that in SLI mode i was getting massive CPU spikes that coincided with the stuttering effect. with SLi off and K-BOOST enabled i get about 85-140 FPS on ultra, but with SLI, i get anywhere from 40-85 FPS.
i tried both cards in both slots on my mobo, and both of them run just fine individually, so i know its not a faulty GPU, but im new to nvidia, so im not sure about drivers. i have updated my BIOS and that has increased single GPU perfomance marginally, but no difference in SLi. figuring that it may just be BF4 i tried Heaven Benchmark 4.0 and got similar results, barely an FPS improvement, much lower min FPS and stuttering everywhere. exactly the same problem in 3DMARK vantage, with a score of 23830 SLi OFF and 24644 with SLi ON.
graphics scores are 25444.1 with SLi off and 26606.1 with SLi on, and the cpu scores are similar but slightly higher with SLi on.
here are my system specs :
windows 8.1
Asus Crosshair V Formula-z motherboard
AMD FX-8350 running at 4.3GHz with a Corsair H100i
16gb Corsair vengeance RAM @ 1633 or so
2 x EVGA GTX 770 SC
256gb OCZ vertex SSD
3-4TB of other HDD space
Corsair AX860i PSU (plenty of juice to power the cards)
i have tried setting my CPU to stock speeds, but no difference as the OC is pretty low anyway. I'm at a loss for what is causing this, i'm thinking there may be a motherboard issue as this isn't the first time i have had multiple GPU performance issues, and both cards are completely fine. the original 7870's did have a legit problem, but im thinking the low performance on the 280x's may have been down to something else.
thanks for any help you can give guys, i really want to stretch the legs of this machine and its disappointing to waste the potential of an extra 770 that cost a lot of money.
