Running Crossfire/SLI with Molex connectors

J

JooK

New Member
I cannot, for the love of god, find a power supply that is not overbearingly expensive that also has 4x 6 pin PCI-E connectors.

The one I have would support my current card in SLI (but that is not desirable) because it only uses 1 PCI-E connection and leaves 1 behind.

However, almost 90% of high performance cards seem to use 2x PCi-E connections, so I was wondering...

I would like to go Crossfire, but I only have 2x 6 pin PCI-E connections.

Would a molex to 6pin PCI-E adapter work just as well or will there be power issues?? I'm going to assume they exist too! :rolleyes:

Thanks
 
Most cards will include a PCIe 6 pin power adapter, your power supply needs to have enough watts and amps. to push the card/s
drivetopciexpress.jpg
 
Its 600w, which I think is enough. I heard there is a warning label on the back of these cards that says its not recommended to use the molex connections, even though they are supplied.
 
I think the biggest reason why, you could have harddrives/blah blah running off the same rail that the PCIe power connector is plugged into. Overload a rail.
 
I have a 600w Rosewill PSU that is crossfire/sli certified (don't know if that means jack). I would like to run a more up to date card with my bigger monitor @ 1900x1200. Benchmark tests show the Radeon 4890 uses 190w at load. I have 1 hard drive, 2 DVD burners and thats all I really use.

The 4890 needs 2x 6 pin connectors. If its not recommended to use a molex connection for performance reasons, then I will stick with a more up-to-date lower end card like the 4850 that only uses 1 connection.

I currently have a GF8800GTS, so I'm afraid the performance increase for 4850 will be minimal. I mainly am changing cards because I always wanted to go crossfire, but Newegg labeled my motherboard as SLI compatible, but its only made for crossfire. It was too late to return the motherboard when I wanted to SLI my GF8800GTS's with my new 1900x1200 monitor (up'd from a measily 17'' 1280x1024 2 months after the build).

Im currently selling my GF to a friend for 50 dollars, and I'm not sure my mobo has an internal gfx card. If I plan on getting the 4850, then the 'upgrade' will only be like 40 dollars but I'll at least have the comfort of knowing that my ATI card is running in an ATI-based motherboard. However, if I can make a more permanent investment, then the 4890 will be better in the long run. Only thing stopping me is my PSU.
 
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If you want to see if you have integrated graphics, look where the I/O backing plate is, and there should be a VGA port. if you do then its only a matter of finding the right drivers.

I would recommend a PSU with more PCIe connections, they are designed specifically for SLI/CF, If your PSU has two 12v rails and you have a 2x molex to 6pin pcie, use one molex from each rail (usually two different cables, but i could be wrong) that way you share the load over both rails and won't overload anything. (unless your PSU is crap!)
 
JooK said:
I have a 600w Rosewill PSU that is crossfire/sli certified (don't know if that means jack). I would like to run a more up to date card with my bigger monitor @ 1900x1200. Benchmark tests show the Radeon 4890 uses 190w at load. I have 1 hard drive, 2 DVD burners and thats all I really use.

The 4890 needs 2x 6 pin connectors.
Click to expand...

If the Rosewill really puts out what it claims, it should push a single 4890 fine. But I dont have much faith in Rosewill P/S.

Are you sure it doesnt have two 6 pin PCIe power connectors? All of the 600W ones I looked at have two. Kinda weird it claims its a SLI/Crossfire certified and only has one PCIe power connector!
 
StrangleHold said:
If the Rosewill really puts out what it claims, it should push a single 4890 fine. But I dont have much faith in Rosewill P/S.

Are you sure it doesnt have two 6 pin PCIe power connectors? All of the 600W ones I looked at have two. Kinda weird it claims its a SLI/Crossfire certified and only has one PCIe power connector!
Click to expand...

I second the wariness of Rosewill. They're fine for low-end systems (In my experience) but I wouldn't push it too far. Also, SLI/Crossfire certified just means it can run two GPU's, it doesn't mean that they're power hungry ones. I think that's something they just put on the sticker to make it look better:P A 4890 would be a pretty big upgrade, and like Stranglehold said, shouldn't have any problems with your PSU, the down the road, after you upgrade your power supply to something a little more reliable, you can get that second 4890 and reap the benefits there.
 
StrangleHold said:
If the Rosewill really puts out what it claims, it should push a single 4890 fine. But I dont have much faith in Rosewill P/S.

Are you sure it doesnt have two 6 pin PCIe power connectors? All of the 600W ones I looked at have two. Kinda weird it claims its a SLI/Crossfire certified and only has one PCIe power connector!
Click to expand...

Yes the PSU has 2 connections. Sorry if I was unclear previously.

Might just get 1 single 4890 ad live with that forever. If future drivers make crossfire more impressive, then I will just get a new PSU.

Thanks for everyones input.
 
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