4850 voltages

[SpookyWillow]

my 3870 was undervolted on the core and it seems i got yet another card with the same problem

since having this powercolor 4850 i have been unable to play grid for longer than 2 minutes as the screen would go black but the pc is still running fine as the game is still playing.

dirt does the same but after 2hours or so,

crysis has done it once.

dropped the core to 500 (was 625) and the mem to 900 (was 990) and suprise suprise it runs fine except that it slows down like slow motion then speeds up again at times.

as i cut up the stock cooler i can't ram it yet so i need to know what the default voltages are for the core and mem so i can check them

 

[yogurt_21]

you psu, while a great one in its day wasn't designed with these cards in mind. do you have access to a more modern one to test?

 

[snuif09]

jeh that PSU probably lacks the amps so get a new one AND DONT GAME i did it with my x1950pro and its in the bin now cause then your screen goes black in 5secs eventually and after that on boot up.

 

[SpookyWillow]

can't get another to test with.

doubt its my psu, rails are solid and tested with a multi meter and upping the core voltage on the 3870 sorted that card out fine with no crashes and that was when i had a Q6600 at 3.6ghz.

just checked amd's certified psu list and mine is listed for a single 4870 - 4850 - 3870x2 - 3870 - 3850 so like i said, i doubt its the psu.

 

[yogurt_21]

can't get another to test with.

doubt its my psu, rails are solid and tested with a multi meter and upping the core voltage on the 3870 sorted that card out fine with no crashes and that was when i had a Q6600 at 3.6ghz.

while it may *seem* solid I'd find a friend who has a newer one to test with. That psu is well over 5 years old. (was launched alongside the ati 9700 pro)

 

[tomcug]

So you should try increasing GPU voltage to 1,15V by performing a pencil mod. If you measure default voltage, it'll be easier to help you. I think your PSU is good enough, I'm even sure that it isn't the source of your problems.

 

[SpookyWillow]

yeah thats my next play of action but i just wanted to know what the stock values are first so i have a good base to start from.

seems 1.2v is default for the core but can't find anything on the mem.

 

[rflair]

Have you updated the BIOS on your Gigabyte motherboard? Its a known problem with Gigabyte boards and newer graphics cards, already seem at least 4 people who had their graphics problem sorted out by updating the MOBO BIOS.

 

[nanohead]

I already RMA's 2 4850 boards since they've been out for the black screen problem. It was the card..... I tried reflashing the BIOS (on the card) and that didn't help.

It sounds like it is vomiting each time it starts to ask for more power when its in 3D mode. So there may be some validity to the PSU question (its usually NEVER the PSU) but once in a while, they could show fine voltage with a multimeter, they can fade when current is called for (like 3D mode and CPU load at the same time).

I actually was having a shutdown problem with my main desktop about a month ago. I took it into the garage, blew out the dust from the machine and especially the power supply, and its as good as new. The PSU might be fine, but it might be overheating at the component level.

 

[SpookyWillow]

1.2v on the core didn't really help.

just seems weird that its only those games that do it, can run 3dmark06 at 1920x1080p with max quality and AA till the cows come home, same with furmark etc.

think i'll RMA the card before i fork out for another psu just yet.

 

[SpookyWillow]

update....

updated to 8.8 drivers and the game ran at stock speed but got major slowdowns,

bought another card and it was the same slowdowns....

tested another psu and the same slowdowns.....

updated to sp1 and voila it works fine and am now running crossfire with no issues at all, didn't think i needed a new psu