Undervolted Pascal - Displays high clocks but internally downclocked? The Pascal Problem [Buildzoid]

[Bacon1]

 

[Smoblikat]

Very interesting, I wonder if this is present on higher end cards like a 1080Ti and Titan? Maybe its a way to artificially gimp the lower tier cards to you cant OC them to get more value, sounds like something nvidia would do.

 

[Bacon1]

Very interesting, I wonder if this is present on higher end cards like a 1080Ti and Titan? Maybe its a way to artificially gimp the lower tier cards to you cant OC them to get more value, sounds like something nvidia would do.

Its not limiting OCing, its... "faking" the hz value while internally throttling.

Fiji does the same thing, but if you give it too much voltage, which is why reviewers who max out voltage got garbage clocks and perf gain on Fiji. It internally downclocked but still showed the clocks as higher.

Pascal seems to do the same, but if you reduce voltage it still shows the high clocks even though its internally running much lower (as seen by the terrible FPS with 2000+ core clocks).

 

[VirtualLarry]

Hmm, side-effects of "clock gating", I guess. Where the clocks being supplied are still high, but the actual computations are gated off of the clocks, so that they "pause" for a little bit. Basically, a form of power-saving, that can be implemented to take effect much faster than changing the clock input and letting it propagate would.

Edit: Interesting video, watched the whole thing. The above is my theory on how it works.

Intel uses a similar mechanism on their CPUs, especially Atom CPUs.

Edit: This is also called, I think, "clock stretching". Or maybe that's something slightly different.

 

[JoeRambo]

It could be something less "sinister" like memory controller starting to spew errors that need to be retried. Guy has +700Mhz on memory, I wonder if even on stock voltage/ stock core clocks it is not getting flaky.

 

[Smoblikat]

I am definitely no expert here, but how would a GPU internally downclock without the software detecting it? Do you think this is somthing newer revisions of GPU-z etc.. will eventually be able to detect? That would make tuning these cards a lot easier.

 

[Stuka87]

I am definitely no expert here, but how would a GPU internally downclock without the software detecting it? Do you think this is somthing newer revisions of GPU-z etc.. will eventually be able to detect? That would make tuning these cards a lot easier.

What the hardware does internally is not visible by the software unless there is an api to see it.