4870 - Top Bios flash / GPU register mod

[dotdcp]

Hey guys,

quick question, yesterday i tried flashing my card with a modified bios i dumped from my card.

i only have 4 voltages available in the registers. i changed the voltage via auto-tune, since i wasnt sure which clock infos to alter. also, i upped the ccc overdrive limit.

the flash was successful, but while booting, always at the same moment, i got a BSOD from atikmdag.sys "SYSTEM SERVICE FAILURE".
(i can only assume, thats because of the ccc limit, or maybe, because there is no fan attached to the card.)

safe mode worked, but i had to reflash the unaltered bios to get the machine to boot normally.

i wanna flash again tonight, and after reading some post here, i decided to use an asus top bios i got from mvktech.

i also read, that 1.35 is a safe voltage for good aircooling (got acc s1 + heatsinks on the vddcs)

now the big question: can i simply change the GPU registers to 1.35V? i have a screenshot attached at the end, maybe someone can shed some light on the matter for me

thanks in advance!
.dcp

 

[dotdcp]

no one active here anymore?

either my card has very poor oc-ability to begin with, or the values dont take.

i modded the top bios via registers up to 1.35V (tried lower values also), even getting those read in gpuz, but i got vpu recovers and even freezes @810. the stock bios runs fine up to 780-790 with stock voltages.

maybe its time to send my trusty 4870 into retirement

 

[Widjaja]

Your card is working now so the chances are the fan is not the issue.

You should try OC with just CCC instead of BIOS flashing and then test in furmark.
Also check your Vreg temps through CPUZ.

The Vreg cooling modules which come with the AC cooling kits are not great plus the overall design of the cooler is generally made for cooling just the core itself.

So your Vregs will most likely be hotter than they were with the stock cooler since there is absolutely no fan cooling besides case fans I am assuming.

Depending on the monitor you have the 4870 could still be a great card.

 

[dotdcp]

i should have elaborated the situation more

the card runs fine, always did. i experimented with the supplied vrm heatsinks, but after going through some alternatives (adhesive sinks on the rams and vrms) i found, that using the stock base plate from the 4870, plus s1 plus additional sinks in the vitec chip works best.

of course i tried oc via ccc first, makes no difference. but its curious that i can max out ccc's settings at stock voltage (790) without a problem (on warm days i could get a vpu recover now and then). but then it wont do 20mhz more with +0.1V.
thats why i suspected the voltages not being applied at all. nonetheless, the performance gain is marginal, so i will leave it at that

thanks anyway!