Originally Posted by OniLink
Hmm, it seems odd to me that G1's have lower voltage limit than stock cards. You said you can't access the measure points, so I suppose you know where they are. Can you please tell me? I removed the stock cooler so I should be able (as soon as I have some free time) to measure the real voltage.
OT: I noticed you synchronized GPC, SYS, L2C and XBAR as Zoson did/suggested. Can you confirm that it improves performance (FPS value)? Some people reported instability with no performance gain at all, some even a FPS loss.
At the moment I have synchronized them too and had not stability issues.
I could be wrong but here is how I came to that conclusion:
My understanding is that stock reference cards with a reference BIOS max out at 1.265V
. This limit is due to BIOS limitations, not hardware limitations
. Modding the BIOS will allow up to
1.312V but that doesn't mean the accompanying hardware can also handle it, it just means it is the the max voltage limit from a BIOS soft mod until you hard-mod.
To be clear, I think my G1's will send
1.312V I just don't think it does any good to push that much voltage because when I allow beyond 1.281V I get VREL perfcaps under load, which seems to me would indicate that VRELs are capped. When I back the max voltage back down to 1.281V in the BIOS, the identical boost clocks are seen but there was no perfcap shown anymore. This is what led me to believe that there must be something
holding the voltage back beyond 1.281V and why I didn't bother allowing any more. I just didn't see any improvement and the perfcap was what I focused on. I really tried to get 1580 stable also but I couldn't so that sort of tells you that something other than just voltage is holding me back, I mean I'm at 45C under full load...the temps are way low and the card has (2) 8-PIN PCIe for juice...
As far as the GPC, SYS, L2C etc I basically saw that many people were syncing them up across many different custom BIOS' so I followed suit. I haven't really done much testing with those settings specifically, most of what I've been testing/tweaking has been with the voltage table, power values and boost clocks. I don't seem to have any issues with them synced either.