HD4890 low mem clock.

Hey guys i just bought a 4890 a week ago and cant figure out why on ATI overdrive the highest my mem clock can go to is 1200mhz. My core clock can go to 1ghz. I keep reading of all these guys running up in the 3-4gh mem clocks so im just confused!

any explanations would be awsome, thanks in advanced.

Since the HD4890 uses GDDR5 which is quad data rate, the effective frequency is MHz x 4.
Meaning that when you're at 1200 (which is impressive clock speed), the effective memory speed is 4800MHz or 4.8GHz

oh damn, thanks dude that makes alot more sense now haha. i was wondering why i would BSOD when playing crysis set at 1200. it runs good at about 1ghz clock. i thought it was the core clock this whole time so i had it set to 850. time to up the core clock.

thx

most 4890's can do 1000/1100 core/mem

but i have seen others that are running 1000-1100/1100-1300

What determines the stability of the setup if the card is supposed to be capable of 1000/1200, but crashes in furmark at 965/1060? do i need fiddle with the pci-e settings or. i cant for the life of me figure out how to update my chipset drivers for my mobo.

i download the chipset driver, and when im in device manager under system, theres like 10 instances of processors, pci bus, etc etc. all are running on drivers from 2006 it shows, so it needs to be updated i just dont know which device to install the update to.

any help would be outstanding, this has me stumped. im using a Gigabyte MA790x-UD4P Mobo btw.

Every card overclocks differently. Just because one card can run on certain clocks, doesn't mean every other card can. Some people get good overclockers, others get duds.

plus your on air and with stock volts you need to up the volts to 1.4 to get higher 1000/1100 and higher