Bitcoin mining HD 6670

Mark wrote:
Hi,
I'm just sending a faulty ATI HD5670 card back. Since these cards are
now hard to get I suspect they will refund rather than replace.
Therefore I will be looking for a replacement. I need something of
equivalent spec. since I play games. However I don't want a card that
draws 100s of Watts since I don't have a huge PSU (400W) and want a
cool & quiet card.
I know there are plenty of HD5670s on ebay but I'm not paying more for
a secondhand one than I paid for a new one (£60).
Any ideas? No newegg links please, since I am in the UK.The used video card market is distorted to some degree, by Bitcoin
mining. ATI cards are good for Bitcoin (GPGPU) mining, while
Nvidia ones aren't (dollar for dollar).

Using the "Crysis Warhead" chart from this page, the HD5670 is 28.7W.
And to me, that would suggest the card has no PCI Express connector on the
end of the card. That's how you spot a low-power card. Cards up to 50W
or so, can draw all their power from the slot. (Designers tend to limit
to about 4.x amps at 12V from the 12V pins in the PCI Express slot, so
in round numbers, it's in the low 50's watt range.)

As a very rough selection metric, you can use the video card memory
bandwidth as a measure of card "class". I'd be using this, to get
into the right ballpark with respect to power. The dollar figure
should also help narrow it down.

Your HD 5670 is 64GB/sec and $99.

The HD 6670 (GDDR5 memory version, not GDDR3) is 64GB/sec and $99.

This HD 6670 with GDDR5 memory, doesn't have a PCI Express power
connector on the end of it, so it's going to be in the 50-55W range
or so max. Xbitlabs is letting me down here - I can't find a power
measurement for some of the newer cards. So I have to rely on connector
configuration as a power estimate. The GPUreview power numbers listed,
are usually on the high side. Xbitlabs makes actual measurements on a
modified motherboard with current shunts.

You can compare that card, to the one you own, with the GPUreview
comparison feature. The 5670 and 6670 are pretty close in terms