Apologies if its already been discussed, but Im curious about this connector and the fact that ATI say its nessecary for overclocking the graphics card using their overdrive utility. I know that you can overclock with just 2x 6pin connectors as I have already with mine using AMD tool.

I understand that they insist using this 8 pin connector to ensure that adequate power is delivered to the card - I believe that a regular 6-pin pcie connector is required to deliver 75w of power @ 12v whereas an 8 pin pcie connector is required to deliver well over 100w @ 12v. But arent most good quality PSUs capable delivering this on a regular 6-pin anyway?

My PSU can deliver up to 18A on each of its rails for pcie - that should mean that my PSU could deliver at least 150w on each pcie connector? If thats the case, then surely a simple adapter to convert one of my 6 pin connector to an 8 pin would allow me to safely overclock with overdrive?

you can use two 6 pins and it works fine, as proven many times and even confirmed by a ATi rep overclocking and all.

Sure, I am already overclocking with the AMDGPU clock tool, and Im getting some pretty decent overclocking at the moment (so far stable at 830/950), but does not having an 8-pin plug actually restrict the overclocking, even though the 6 pin connected to it can actually deliver all the wattage the card needs?

I would like to know also as i am going to start overclocking soon.

Biglunn said:

I understand that they insist using this 8 pin connector to ensure that adequate power is delivered to the card - I believe that a regular 6-pin pcie connector is required to deliver 75w of power @ 12v whereas an 8 pin pcie connector is required to deliver well over 100w @ 12v. But arent most good quality PSUs capable delivering this on a regular 6-pin anyway?

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The problems is not that the rail is incapable of supplying the wattage, or that the 6 pin is unable to supply the current. But the simple fact the 8 pin is "rated" at 150w. If you take a look at an 8 pin you'll notice the same number of 12v conductors as a 6 pin. Just 2 more commons.

Biglunn said:

My PSU can deliver up to 18A on each of its rails for pcie - that should mean that my PSU could deliver at least 150w on each pcie connector? If thats the case, then surely a simple adapter to convert one of my 6 pin connector to an 8 pin would allow me to safely overclock with overdrive?

Click to expand...

It may not be able to supply 18A on each rail at the same time. Don't forget rails can't be added together cumulatively. Your PSU can supply 680w@12V that's 56A. But traditionally the wattage for each rail is controlled by overcurrent limiters, normally around the 240VA limit. However a lot of PSU's only have one giant rail, regardless of advertising.

Biglunn said:

If thats the case, then surely a simple adapter to convert one of my 6 pin connector to an 8 pin would allow me to safely overclock with overdrive?

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The nearest you may see is 2xpins to 8pin. The manufacturers want the 150W feed direct to the PSU. You may be able to get a replacement lead for a modular PSU.

Nothing to stop you making one custom like this:




You may find a few custom adapters if you look around.