Bitcoin Forum

Hi,

I've checked the graphic cards in the mining equipment wiki and found some candidates I would buy for my first mining rig. But I'm still wondering why there is no statement about required graphic card memory in the wiki. Is it not important for the performance? Can I go with some small graphic card memory like 1 Gb or is it better the have some bigger one?

Another question: I've read that it tends to be difficult to combine two entirely different graphic cards like 6970 and 5850 in the same mining rig. Would it also be a problem to combine two different models of the same series, like a 6970 with 1 Gb memory with another 6970 with 2 Gb memory?

Martin

Memory is totally irrelevant when it comes to mining, so less memory=cheaper card for same result. Furthermore, memory produces heat, so many miners under-clock their memory as much as possible.

Thanks, that's good to know.

Purely for mining, I'd go for the card with the smaller memory. They tend to be a little cheaper, and I suspect that it will save some power consumption. Downclocking the memory also has no effect no hash-rate, but can give substantial heat and power savings.

I have noticed on my 5830's and my 6870's a reproducible increase in hash rates by 5-10 mh/s by as a result of downclocking to 200 mhz.  This is in addition to the decreased heat generation.  I have no idea why this happens.

actually, downclocking reduce memory latency in Radeons case and for mining context thats far more handy, than throughput[which is matter in case of gaming workload/appz]cuz tiny amounts of data need to be moved VERY quick.

Never noticed an increase, but I can see why it could happen. I'll have a play around with that later. Thanks.

some tweakers allow to modify timings directly, like [shipped-with-suspiciously-behaving-kernel-space-driver]Ati Tray Tools, but you can see how timings change with clocks, by looking into BIOS settings.