After further testing with the software mod, I decided to embed the settings within the bios. Since I also sporadically experienced the infamous striped crash I also normalized the voltages across the various powerplay states, that is because I was able to confirm that every crash took place during a sudden switch between high and low states. As I presumed, it wasn't an issue of frequencies dropping, as much as voltages.
Here is a table containing the new settings for a stable Sapphire HD 5870 Vapor-X OC Edition, together with some improvements to the fan management, which keeps the GPU cores within 75 degrees celsius even under long hours at full load (the stock settings never push the fan beyond 55%, allowing the board to reach 87 degrees, which I don't like).
The following settings were applied to a fresh dump of the bios, using TechPowerUP's Radeon Bios Editor 1.25 + WinFlash 22.214.171.124.
Clock info 00:
850/1250 Voltage 1.063 (original voltage 0.950)
Clock info 01:
157/300 Voltage 1.063 (original voltage 0.950) [Aero/2D state, overvolted to avoid the vdrop when switching between 3D and 2D, frequently happening during loading screens]
Clock info 02:
875/1250 Voltage 1.163 (original voltage 1.063) [Pushed the medium state up to 3D, since my system would ignore that one, with this I can get the card to correctly go @ full speed in games]
Clock info 03:
875/1250 Voltage 1.163 [untouched]
Clock info 04:
600/900 Voltage 1.063 [UVD state, slightly pumped up]
Clock info 05:
875/1250 Voltage 1.163 [No idea when this is used, since the state structure that contains it has the same name as the main one, normalized and pumped up]
Clock info 06:
875/1250 Voltage 1.163 [Same as clock info 05]
Tmin: 40 Degrees
Tmax: 75 Degrees
Duty cycle min: 15%
With these settings I completely god rid of artifacting and so far couldn't experience any stripe crashes. If your card is acting up, I strongly suggest you normalize your power-play settings across the board, especially avoiding the gap btween 0.950v and 1.163v in the low/high modes.
Last edited by voidburn; May 26, 2010 at 03:48 PM.
Reason: Added RBE+Winflash versions used to accomplish the dump/write of the bios.