Dell Optiplex 790 Graphics Card

[mc605700]

Hey everybody,

I'm wondering if anybody has ever put an add in graphics card in a Dell Optiplex 790. I ask because I'm looking to put a Radeon HD 6670 into mine but according to the Dell spec the x16 PCI-e slot is only rated for 35watts. I'm wondering if that's just Dell being conservative because the computer only has a 250watt PSU or if the socket isn't physically capable of handling more. I don't want to end up burning up the motherboard but the dell recommended HD6450 is pretty anemic. I'm only looking to do occasional light gaming with this machine. Has anybody tried it? Any suggestions?

Thanks!

 

[mc605700]

Anybody?

I've found lots of people asking this question. Someone has to have tried it.

 

[bobusboy]

ATI recomends that both the 6450 and the 6670 use a 400 watt power supply.

IMO you shouldn't have a problem due to the PCI-e slot, but the power supply might not be able to push enough watts to support the GPU if it's under heavy load.

For what it's worth, my little brothers PC has my old 6790 in it and it only has the stock HP 300 watt PSU and it runs perfectly fine.

 

[mc605700]

Thanks,

I'm less worried about the PSU being able to supply the 6670 than I am that the pci-e x16 slot is only supposed to be rated for 35watts.

 

[bobusboy]

IMO they're being conservative.

Try asking on the Dell forum.

 

[mc605700]

Well, I've found the question on the Dell forum but they won't give a straight answer. They just say that the only cards that are validated for the 790 are the HD6350 and the HD6450. Or that the socket is only rated for 35w.

 

[sk1939]

The 790's we have only have 6450's, but then again they are the SFF which have additional cooling issues.

 

[wolfram23]

Power

PCI Express cards are allowed a maximum power consumption of 25W (×1: 10W for power-up). Low profile cards are limited to 10W (×16 to 25W). PCI Express Graphics 1.0 (PEG) cards may increase power (from slot) to 75W after configuration (3.3V/3A + 12V/5.5A).[8] PCI Express 2.1 increased the power output from an x16 slot to 150W so that some high-performance graphics cards can be run from the slot power alone.[9] Optional connectors add 75W (6-pin) or 150W (8-pin) power for up to 300W total

http://en.wikipedia.org/wiki/PCI_Express

Now I'm assuming you are using one of the modern ones featured here http://www.dell.com/ca/enterprise/p/optiplex-790/pd

In which case it should have the 75W spec for the PCIe slot. Where did you find the 35W info?

That all said, a 250W PSU is *** and you should upgrade that first. Get an Antec or Corsair 430W unit.

Then you can put whatever GPU you want in there.

 

[mc605700]

Dell only offers a 300w psu for this model. And being Dell, their PSU is not a standard type so I can't just get a replacement. That's why I'm looking at low power video cards that don't require six pin power. The info about the PCI-E x16 slot is on page 19.

http://www.dell.com/downloads/global/products/optix/en/optiplex-790-tech-guide.pdf

Even if I could upgrade the PSU. If the slot in the Mobo can't physically handle a 75w load like the standard PCI-E x16 slot there's no point in any upgrade beyond the HD6450.

 

[wolfram23]

It would be great to know which PC you have. MT, DT, SFF, USFF?

The PSU should definitely be replaceable, PSU sizes are standardized including the small form factor ones.

However, it does seem that motherboard is the limitation. Never heard of a mobo restriction like that. I guess this is another reason a lot of people don't like Dell.

 

[sk1939]

The motherboard restriction is there because of the sizing of the power supply units, and for the SFF and USFF, the cooling requirements. It's easier to standardize it across the line as well which is probably why the MT has the same restrictions.

 

[mc605700]

I have the DT Model running a Core i3-2100. I've done the rough power usage calculation and if I add an HD6670 even with everything running flat out I should only be drawing about 200w. I just don't want to sink $80-$90 into a half height card that isn't going to work. Or worse is going to fry the traces in my PCI-e x16 slot or motherboard. I've got a pretty limited budget for this. I can't afford a PSU and Graphics Card and I really can't afford to fry the computer. In a perfect world I'd scrap the whole thing and just get a new case, PSU and Mobo along with a new Graphics Card but that ain't going to happen.

 

[sk1939]

With the 35W limit, it's not going to run unless you can get power from another source via external connection.

 

[mc605700]

With the 35W limit, it's not going to run unless you can get power from another source via external connection.

So you think Dell is serious about the 35w limit?

 

[sk1939]

I do indeed, especially since they build their PC's to such tight tolerances. This is doubly true if your PC is under warranty.

 

[mc605700]

I do indeed, especially since they build their PC's to such tight tolerances. This is doubly true if your PC is under warranty.

Bummer. That's what I was afraid of. There's a reason I don't generally go for Dell PCs. It's these little "Gotchas!" that I find with their machines. I was hoping someone had a positive experience of actually using something other than the HD6450 with a 790 and could report good results. So far I haven't heard anything from anyone who has tried or been successful.

 

[sk1939]

I know the feeling; the SFF's are worse in the sense that Dell was nice enough to include 2 PCI-e x16 lanes, but orientated them so that you have to use low-profile cards instead of the extra $3 to add a riser card. That, and all the one's we ordered came with laptop HDD's because someone screwed up along the way.

 

[Guest]

I have a radeon 6570 (44 watt ddr3 version) running in a SFF optiplex 780 with a 230W power supply. runs fine!

avoid fanless cards in this small case, my previous fanless 5450 used to overheat.

 

[mc605700]

I have a radeon 6570 (44 watt ddr3 version) running in a SFF optiplex 780 with a 230W power supply. runs fine!

avoid fanless cards in this small case, my previous fanless 5450 used to overheat.

That sounds great and what I was hoping to hear. Can you tell me what games you play? Do you really tax the video card?

 

[onefortheroad]

That sounds great and what I was hoping to hear. Can you tell me what games you play? Do you really tax the video card?

I haven't had the sapphire 6570 very long, also I haven't done much gaming in the last decade or so, so probably the older games I have missed will keep me happy for a while

Portal 1, Half Life 2 and Team Fortress 2 all run fine on max @1080p.
Portal 2 stresses the card more but still runs fine on ~max @1080p (I don't bother with max AA)
Dirt showdown ran fine on max 1080p.
Am running a q9550 quad core with 8GB of ram.
the gpu sits on 100% in portal 2, and gets up to about 80 degrees when it's pushed. However the fan control only operates at about 50-60% even at this temperature. all clock speeds are stock.

I haven't tested whether it can run crysis, but youtube says yes

 

[mat347]

I've got two GT 430's overclocked to 833 in a 790. The I5 2400 folds fine(100% duty on all cores and both GPUs). GPUs get to around 70C under load which is high for me, but still within spec.

You should be fine!

 

[Mousemonkey]

This topic has been closed by Mousemonkey