305 Watts enough for this system?

PSUs: The source of DC power for all components in the PC & often a big noise source.

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johnniecache7
Posts: 332
Joined: Wed Jan 17, 2007 8:10 pm
Location: Toronto - Ontario - Canada

305 Watts enough for this system?

Post by johnniecache7 » Thu Mar 14, 2013 11:15 am

Hello,

I've Dell Optiplex 755 mini-tower (mid tower) with the specs below and I'm sure it will run my HIS AMD Radeon HD 7750 1GB DDR5 , Sound Blaster Audigy SE PCI sound card without issue but I'd just like to double check. A larger standard ATX PSU will fit and I've got one but the issue is cable management the stock tower has zero room for extra cabling. The orignal PSU cables are custom fitted in length and size for the tower. I'm guess The system won't even draw 200 watts.

Dell Optiplex 755

Dell 305 Watt PSU
Intel Motherboard
Duo Core 2 E6700 (Conroe, 65 Watt)
4 x 1GB Sticks DDR2 Memory
Onboard Video
Onboard Sound
Onboard NIC
PCI-Ex x16 slot
2 x PCI slots
DVD Burner
4 x USB 2.0 Devices

Adding

Sound Blaster Audigy SE PCI Sound Card
HIS AMD Radeon HD 7750 1GB DDR5

edh
Posts: 1617
Joined: Mon Mar 17, 2008 1:49 pm
Location: UK

Re: 305 Watts enough for this system?

Post by edh » Thu Mar 14, 2013 11:31 am

Less than 150W I would think.

A word of caution: Dell have been known to use a non-standard PSU connection in some systems. The connector might be the same but the cable arrangement may be different and potentially won't work. Google for more ideas on this and how to fix it.
Raijintek Metis: i5-6400, Scythe Ninja 4, Asus Z170i Pro Gaming, 8Gb RAM, GTX 950, Crucial 250Gb M.2, Seasonic X-400

johnniecache7
Posts: 332
Joined: Wed Jan 17, 2007 8:10 pm
Location: Toronto - Ontario - Canada

Re: 305 Watts enough for this system?

Post by johnniecache7 » Thu Mar 14, 2013 11:47 am

edh wrote:Less than 150W I would think.

A word of caution: Dell have been known to use a non-standard PSU connection in some systems. The connector might be the same but the cable arrangement may be different and potentially won't work. Google for more ideas on this and how to fix it.
I checked on Google on Dells forums they say uses standard ATX PSU 24 pin connector but yes, cable management would be a mess, I was going to try and shoe horn the Antec VP450 450 watt PSU into it but with the cable layout it doesn't seem possible. It's not the best tower but it will meet the needs it's going to be used for. I just didn't want to blow up a good working computer. I'll stick to the stock 305 watter as I believe FSP made the PSU for Dell in these.

This not my system (In the video) but it's the same as what I'm dealing with and my HIS AMD Radeon HD 7750 1GB DDR5 is the same size and same GPU cooler on it. From what I see there just no room any place for cabling.

http://www.youtube.com/watch?v=V4XhllvS ... 1361356060

BillyBuerger
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Re: 305 Watts enough for this system?

Post by BillyBuerger » Thu Mar 14, 2013 12:58 pm

We have a couple of the Optiplex 755s here at work. I measured the power of one of ours here with a C2D E6750, 4x1GB, and a Radeon X1300 to be about 62WAC idle and 103WAC under heavy CPU usage. The 7750 runs off the PCIe slot directly (no external power needed) so the max is 75W. The 150W estimate probably pretty accurate.

The Dell PSUs in these are just about standard ATX. Connectors are all standard. Only difference is that they are slightly taller. Mounting holes are the same even. So you would have no problem dropping a standard ATX PSU in there. You would actually end up with a little bit of extra space between the PSU and motherboard. Might help with cable management.

You can use these Dell PSUs in standard PCs. Assuming you have the extra room around the PSU for the added height. I have one of their 80+ silver models in an Antec mini-P180 case. Had to cut up the case a little to fit it in though. And since the 24-pin cable is so short, an extension is pretty much required.

johnniecache7
Posts: 332
Joined: Wed Jan 17, 2007 8:10 pm
Location: Toronto - Ontario - Canada

Re: 305 Watts enough for this system?

Post by johnniecache7 » Thu Mar 14, 2013 1:08 pm

BillyBuerger wrote:We have a couple of the Optiplex 755s here at work. I measured the power of one of ours here with a C2D E6750, 4x1GB, and a Radeon X1300 to be about 62WAC idle and 103WAC under heavy CPU usage. The 7750 runs off the PCIe slot directly (no external power needed) so the max is 75W. The 150W estimate probably pretty accurate.

The Dell PSUs in these are just about standard ATX. Connectors are all standard. Only difference is that they are slightly taller. Mounting holes are the same even. So you would have no problem dropping a standard ATX PSU in there. You would actually end up with a little bit of extra space between the PSU and motherboard. Might help with cable management.

You can use these Dell PSUs in standard PCs. Assuming you have the extra room around the PSU for the added height. I have one of their 80+ silver models in an Antec mini-P180 case. Had to cut up the case a little to fit it in though. And since the 24-pin cable is so short, an extension is pretty much required.
Did you have any problems with the SATA power contectors? I'm told that if they're not right angle it might cause issues? Antec VP450 doesn't have right angle SATA power contectors but most budget PSU don't. I see in most of the reviews the HD 7750 drawing about 47 watts, I use them in few my systems since I only game 1366 x 768-1440 x 900, quiet and cheap. Great, if I can get into the case without making a mess it would be nice, maybe I'll try after all, Thank you for the information.

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