How to get RT GPU to Overclock?

[biochemical_animations]

So my 980 ti goes back to the P2 state when I open max, lowering my memory clock to 3305. It should be 3505 or higher (OC). Any idea what I can try?

[biochemical_animations]

nevermind, I just figured it out, I ran nvida inspector and set the P2 profile to run at a higher memory clock and since max opens and runs at p2 as well as rt, this worked to run my gpu memory clock at 3505 for rt gpu rendering...yay!

[Alex_M]

Good to hear that you found the problem.

Maybe a stupid question but does memory clock have any effect with GPU rendering? I thought that only the CUDA cores participate in the rendering process.

[biochemical_animations]

Don't know, I'm still figuring this out...still have testing to do to see if OCing boosts render speed.

[Alan Iglesias]

Maybe a stupid question but does memory clock have any effect with GPU rendering? I thought that only the CUDA cores participate in the rendering process.

The only stupid question is the one not asked...

As I remember, when I was messing with GPU OCing the memory clock did affect GPU rendering time. Perhaps not as much as the Core clock, but I think it made some difference...you might want to try it though as that memory was from a few years ago...

-Alan

[Alex_M]

Ok, just tried to overclock the memory of my GTX 980 (non Ti) but MSI Afterburner wouldn't let me to. I can overclock the GPU core. It resets the memory clock to defaults as soon as I apply the new memory clocks. I tried also with EVGA Precision. Some people on the internet say that they managed to OC the memory with. I was able to apply the new memory clocks without resetting to defaults but I found that in reality, as with MSI Afterburner, it too can't OC the memory. I checked the memory clock in GPU-Z and it was still at factory default even when I've applied the OC in EVGA's software. Is it possible that Nvidia have locked the memory OC abilities on my card? Anyone else having the same issue?

[super gnu]

i used nvinspector to oc my titan x. core to 1470mhz and memory to 4100 mhz. i dont know about the other oc solutions but in NVinspector, you have to be careful to set the clocks for the P2 state BEFORE you open max or any other gpu intensive app or the clocks dont stick.

and from my testing, overclocking the memory had a large effect on gpu rendering speed, similar to increasing the gpu clocks.

[biochemical_animations]

Ok, just tried to overclock the memory of my GTX 980 (non Ti) but MSI Afterburner wouldn't let me to. I can overclock the GPU core. It resets the memory clock to defaults as soon as I apply the new memory clocks. I tried also with EVGA Precision. Some people on the internet say that they managed to OC the memory with. I was able to apply the new memory clocks without resetting to defaults but I found that in reality, as with MSI Afterburner, it too can't OC the memory. I checked the memory clock in GPU-Z and it was still at factory default even when I've applied the OC in EVGA's software. Is it possible that Nvidia have locked the memory OC abilities on my card? Anyone else having the same issue?

Yep, exactly what happened to me, but I got around it.

From what I learned 3ds max prompts the nvidia driver to put the gpu in the P2 state. The only state OCing the memory in MSI AB will work is P0.

If you open nvinspector, it will tell you the performance state (P-state). The driver puts the card in various states based on what application is running. P0, P2, P5, P8...google them to look up what they are, basically different power, lower clock, etc, if you are not stressing the card.

So, since max forces P2, the only way to get memory to OC is to create a new GPU bios from your existing one, and change the P2 state to whatever clock speed you want. To figure this out, I downloaded heaven and msi AB and nvinspector, I ran heaven and observed p2. I had to disable/enable my display driver in device manager for win7 64, then I ran heaven and I got p0, the overclocking p-state...msi then let me OC my memory.

I'm currently testing this, but my goal is to use the above method, find my stable memory OC using msi ab, then put it manually in my saved bios using Maxwell Bios Tweaker under the p2 power state, and flash my gpu bios using nvflash v5.287 with the tested/stable OC value. This should run the memory at the OC in max and vray rt gpu cuda mode at the p2 state.

Be careful about flashing your gpu bios, because you can brick it.

For me, since I have a 980 ti classified, it has a switch for 2 bios', one is normal and one is LN2 (liquid nitrogen or water cooled I think)...I'm using my stock air cooler, I think its called acx 2.0, or something, but my temps stay at below 84 C.

So I mess with the LN2 bios, leaving the normal bios alone in case I mess up.

I save a copy of my LN2 bios for later in case I mess up and have to put it back to stock. I do this using GPU-Z. Then I open my saved stock bios file with MaxwellBiosTweaker and make one adjustment (that is all I know at this point). Simply setting the p2 memory clock state from 3305 to 3505. Save the modified bios file and open cmd prompt as admin, cd to the nvflash folder on my c drive, type this command

nvflash --index=0 -6 bios.rom

(--index=0 means my 1st card on my mb...I have 2 980 ti on my mb) If you have one card, I think only run this:

nvflash --index=0 -6 bios.rom

-6 is for overcoming some admin privilidges or something, and bios.rom is the file name of the bios you want to flask with.

press y when prompted (I think it's only once)

I get a confirmation my bios was updated successfully (I ignore the errors about cert checks not being valid or something like that), reboot, and now my P2 memory runs at the modded value.

I hope this helps.

So far, I successfully flashed my ln2 gpu bios to get the p2 memory clock to 3505...I have not OC'd it beyond that yet...but so far that has worked.

[biochemical_animations]

OK, I just figured something else out.

After I disable/enabled display driver, ran heaven and saw p0, ran msi ab and upped my memory to a new value, pressed apply and it stuck, I kept MSI ab open and ran max, max put the gpu in p2, but the memory stayed at the new value I set when it was in the p0 state when heaven was opened...so I guess flashing the bios is not necessary...just do the display driver disable/enable trick, set the memory clock, leave it, and open max, p2 will run the new clock.

[Alex_M]

OK, I just figured something else out.

After I disable/enabled display driver, ran heaven and saw p0, ran msi ab and upped my memory to a new value, pressed apply and it stuck, I kept MSI ab open and ran max, max put the gpu in p2, but the memory stayed at the new value I set when it was in the p0 state when heaven was opened...so I guess flashing the bios is not necessary...just do the display driver disable/enable trick, set the memory clock, leave it, and open max, p2 will run the new clock.

Sounds good! Did you observe a rise in performance in RT with the new memory clocks and how big was the improvement in percent?

[biochemical_animations]

Sounds good! Did you observe a rise in performance in RT with the new memory clocks and how big was the improvement in percent?

Still testing...I'll let you know what I find.

EDIT:
OK, I got a 7.84% increase in render speed by increasing my memory clock on one of my 980ti's on my ws, from 3304 to 4000 (+701 OC)...+201 was done in the bios (from 3304 to 3505) and +500 was done in AB. I may have been able to get more OC, but I got nervous.

My temp was 81-84C on either mem setting, 3304 or 4001.

I also did a small prelim test on my core OC, and got an addtional 4.41% increase. I think I can OC my core more, I just did a small core increase of +40, I haven't combined them yet, but that right there might be 12.25% increase in render speed just by OC, combined with second card, maybe 24.5% increase in speed overall. I'll have to test a bit more, cores are a little more involved given the volt increase...but that right there was worth the OC test. Time will tell if I get that or not in real life. Maybe I could play with the ray bundle size and rays per pixel to squeeze a bit more...we'll see.

Also, my test scene had no textures, only an HDRI dome and a high poly refractive object, so maybe a scene with more textures might benifit more from the memory clock increase...I don't know.

[Alex_M]

Did anyone manage to overclock the core clock of 1080 ti in P2 power state? I was trying to overclock my 1080 ti today but after reading the whole nvinspector P2 state trick on this thread I still couldn't change the P2 state core clock of the card. From what I read, the GPU uses the P2 state GPU clock when the CUDA cores are working, not the P0 state. So I went and enabled "Unlock Max" in nvinspector in the P2 state dropdown but the core clock kept reverting back to 570 mhz no matter what value I applied. Changing the core clock in P2 state of my GTX 980 on the other hand works fine and the clock sticks after applying it unlike my 1080 ti. Is it possible that nvinspector doesn't work well with 1080 ti? I'm using version 1.9.7.8 of nvinspector, the latest one, but still it was released 4-5 months before 1080 ti was so maybe it's not compatible with the new GPU?

[biochemical_animations]

Hey Alex,
I can't help you with the 1080 ti, but I couldn't get my 980 ti's to overclock using software. The drivers control putting the card in P2 and the only way I could get an overclock was to flash the 980 ti's bios. Flashing the bios lets you set values for the different P states of the card...so even in the P2 state, I get over locked values that I setup in the bios. HOWEVER, FLASHING THE BIOS INCORRECTLY COULD BRICK YOUR CARD, rendering it useless.

I purchased 980 ti classified's that have a dual bios switch, just in case a bios flash went bad, I could switch to bios #2 and still use the card. I've flashed a good amount of times and all went well.

You can set temp thresholds for fan speeds and RPM rates and clock speeds for the gpu and memory, for whatever p state.

The info on flashing gpu is found on the overlockers site. You need some software, free, like inspector, nvflash, a copy of some else's bios only for reference, then you save your bios, mod it, then flash using you modded bios. You should read all about it beforehand and understand the risks. I'll see if I can located a thread for you and put the link here.

One thing about overclocking, is to test your overclock with heaven benchmark and msi afterburner for stability to get stable values before flashing. If you flash with values that are not stable, the card could freeze, but perhaps a reboot and re flash to lower values might work.

Worse that could happen is your out $700 for the card...best that could happen, is it works and you become a master at overclocking the 1080 ti and get a faster rig and can help others.

If it were me, I'd prolly do it. Good luck.

[biochemical_animations]

Ok, here is the thread I used, but I also read a bunch of other stuff too, from that site and others.

http://www.overclock.net/t/1590323/e...k-cooler-users

here is a 1080 ti thread...I have not read it

http://www.overclock.net/t/1624521/n...ti-owners-club

[Alex_M]

Oh, ok. I just bought the 1080 ti so I'm not too keen on risking breaking it just a few days after purchase. It's still at least 2 times faster than my old GTX 980 so I'm happy.