Radeon HD4890 in a Dell Precision T3500 - is it possible?

ojai00

Diamond Member
Sep 29, 2001
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The Radeon HD4890 requires two PCI-Express 6-pin connectors. The 525W power supply in the Precision T3500 only appears to have one PCI-Express 6-pin connector.

The video card came with a Y-cable that has 2 4-pin molex connectors on one end and a 6-pin PCI-Express connector on the other end. However, the power supply only has one 4-pin molex connector.

Any idea if I can use this video card in this workstation? I'm not good with calculating power supply requirements :(

Thanks in advance!
 

ViRGE

Elite Member, Moderator Emeritus
Oct 9, 1999
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You would need to split the Molex. The way it works is that the Molex->PCIe adapter takes 12v lines from each Molex, hence you need two of them. However I'd be really antsy about doing so since Molex wasn't designed for as much power as PCIe was.
 

jthunderloc

Senior member
Dec 28, 2009
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maybe.

the biggest problem with running the molex to PCI adapters is your now drawing a butt load of power on the same rail as the hard drives and most likely the motherboard. the best way to do it would be splice a second PCI adapter off of the first as it usually draws power from its own rail.

525 watts should be ample power for a single 4890, they draw around 160-175 watts at max load.

-Wes
 

fffblackmage

Platinum Member
Dec 28, 2007
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525 watts should be ample power for a single 4890, they draw around 160-175 watts at max load.
There's also the maximum wattage output on the 12V rail the PSU can provide, which may not be up to 525W.

@OP
Well built PSUs nowadays have strong 12V rails, but some crappy or old PSUs will have relatively weak 12V rails and pointlessly strong 3.3V and 5V rails.

You should check what kind of current output your PSU can provide on the 12V rail to be sure it can support a 4890 to be safe. The fact that there is only a single molex and a single PCIe power connector may mean the PSU isn't designed for such a large load.
 

ojai00

Diamond Member
Sep 29, 2001
3,291
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Thanks to all for the input. The workstation is running a Hipot power supply so my guess is it is not a high quality one. I've seen some posts that the Dells are using standard ATX power supplies now so I should be able to switch it out with a higher quality one. Can this be confirmed?
 

betasub

Platinum Member
Mar 22, 2006
2,677
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Modern Dells that I've seen inside do have standard ATX PSU and connectors. But that's no guarantee that yours does. Look inside and check PSU size to fit a replacement, plus connectors to make sure they match standard reference (pics available on any PSU / motherboard manufacturer, vendor or review site).