Graphics card power connections

[CR34M3]

Hey everyone, this might be a bit of a silly question – but please indulge me.

Up till now I was running quite happily with my two ATI HD4870s but decided to do a mini-upgrade after getting two HD6790s for cheap-cheap. Now, the HD4870s had 2x 6pin PCi-E power connectors each, but the HD6790s only have one each: does this matter in any (performance related) way? I mean, all standard HD6790s use the same GPU chips, and the brand only affects the cooling system and bundle, right?

Seeing as I’ve already bought the cards, the answer to this question won’t really change anything, I was just wondering for future reference. Might make me think a little more on the brand in the future.

 

[Pada]

The high performance cards does require more power. Seeing that the hd6790 cards are two generations later than the hd4870, they should be much more efficient.

From what I've seen so far, the hd6790 is only slightly faster than the hd4870, but I suppose that they would be quite a bit faster in crossfire.

Just take note that some brand and models might be overclocked, so just make sure to run both cards at the same clock and memory speeds.

Sent from my Nexus S using Tapatalk

 

[CR34M3]

Thanks for confirming my suspicions.

From what I've seen so far, the hd6790 is only slightly faster than the hd4870, but I suppose that they would be quite a bit faster in crossfire.

Like I said, “mini-upgrade” and “cheap-cheap”. I’m setting up a second relatively competent gaming pc, so I’m so much replacing the 4870s as redeploying them.

 

[Rock Bottom Computers]

Both cards, the HD4870 and HD6790 uses approximately the same amount of power. (i.e AMD specify a peak 150watt)

Some HD6790 uses two 6 pin connectors. (see system requirements in link below)

http://www.amd.com/UK/PRODUCTS/DESK...6790/Pages/amd-radeon-hd-6790-overview.aspx#2


What this means is that in your case the graphics card rely on one half of the power requirement (75watt) to come from the PCi-e 2 slot itself. The Pci-e 2 slot is said to deliver a max of approx 75 watts. The one 6 pin and PCi-e bus power then, in combination, can deliver about 150 watts.

You mentioned you thought this to be a minor upgrade, but it is a major upgrade in a sense.
The HD6790 is about 10% faster, but more importantly is Direct X11 capable while the HD4870 is not.