Guide for Selecting a Power Supply

[beta_tester]

Excellent!
Many congratulations, upgrading ones own computer is always so satisfying I have found.
Please let us know how you get on.

Kind regards john

[Clarke-PC]

My question is a few replies back.

To replace my trouble some power supply do I NEED to get one that has a fan that faces the rear?

I bought one (Diablotek DA 300) and the fan faces up (or down if you mount it that way) and I think it is not exhausting the air enough.  In other words the heat of the power supply is trapped in the case.

When I look at specs on the web and even the package of power supplies do not mention which way the fan(s) are oriented.

Clearly the dimensions are important (already learned that lesson).  And wattage (and efficiency) are important but I could not find a resource that talked about fan direction. Being an HP system I thought this would be an easy question for the engineers who design cases to answer.

Thanks.

[beta_tester]

Hi Clark

A very important but neglected detail is air flow in and out of our computer. It is no good havIng many fans but a vortex in the case 🙂

You mention your fan faces up or down, if pointing up it really must have the case type that the air is expelled from the case through slots etc. and not Trapped against a solid case top 🙂

1. Most psus I have seen have one at the rear to expel the air from the back of the case. Some also have an additional fan that blows down across the motherboard, CPU, memory and graphics card.  But it will have been (or should have been), by working out cubic air flow so that that specific fan blows across the components but the other case fans expel the air or you will simply have a vortex like part in the middle of the case that leaves trapped heated air there (not a good idea :-).
2. Unless your case is designed that way replace a psu with one of the same orientation, ie where fans expel the air and it's direction.

Hope this helps, kind regards john

[Quiller18]

Is there a way to replace the default PSU in HP 8200 CMT to be quiet! Dark Power Pro 650W 80PLUS Gold 10, 12.8 dB, 4/1 (OCK) 12V?
Replacing the PSU is necessary due to the need for a GPU demanding an external power supply (HD7970-DC2-3GD5)

Hindered by two problems.
* Be quiet! is smaller than the default PSU. Is there an adapter for smaller PSU?
* What is PWRCMD? I've never gonna use the "Feature" HP. PWRCMD is completely new to me. Is the motherboard will work without the cable?

Thank you for your help and sorry for my english ^ ^

[beta_tester]

Hi Quiller18

I think you may have problrms, here are 2 discussions about similar prtoblems that will help you:
http://h30434.www3.hp.com/t5/Desktop-Hardware/replacing-PSU-on-HP-COMPAQ-8000-ELITE-Convertible-Mini...
and
http://h30434.www3.hp.com/t5/Desktop-Hardware/Replacing-PSU-on-HP-Elite-8100-CMT/td-p/58853

Trust this helps, kind regards john

[Big_Dave]

Hi Clark,

HP does in fact have PC cases with slotted air intake vents along the top edge.  The case used for the HP e9280t is a prime example.  This allows the power supply fan to pull cool air from the intake vents along the top and exhaust hot air out the back of the PC. 

I haven't seen many reverse air flow power supplies but that doesn't mean that they don't exist.  I would not recommend using one in a PC.

Many custom PC cabinets allow orientation of the power supply unit  (PSU) so that cool air can be drawn into the PSU by the PSU fan and then exhausted out the rear of the PC.

It doesn't make much sense to expel hot air from the PSU into the insides of a PC when the video card and CPU are in need of cool air.

[godspeed]

can anybody suggest me a decent psu under$20?

Looking for a good gaming gpu under $60

My PC is HP Pavillion A6340in

Please Help!

[Big_Dave]

Hi godspeed,

I haven't seen any decent "gaming" power supplies for under $20.  Modern PC games generally require a fairly powerful discrete video card.  Depending on the games, this usually leads to a 500+ watt power supply.

[davmat787]

I too need to upgrade the power supply in my HP 8100 Elite tower from the default 320 watt, to one around 500 watts.  And like others, I ran into the problem with the current power supply using proprietary connectors on the motherboard.

Has anyone figured out which power supply will work in an HP 8100 Elite tower?   

Many thanks for any help!

edit: After posting this, I came across a solution that many looking to upgrade their PSU to support a GPU might be interested in.   It is a separate power supply that slides into an empty 5 1/4" bay that is designed to specifically power a PCIe GPU.   So, no need to replace the current power supply that is proprietary and hard to find, just add one of these.   I hope it is okay to link to a non HP part on newegg, if not I apologize.

I would still like to know if their is a regular PSU that will work in an 8100 Elite as that is a cleaner solution.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817104054

[beta_tester]

Hi Davmat

I believe these forums are exactly designed for this purpose of helping provide solutions to fellow HP users problems. I really appreciate you taking time to let us know of this solution I certainly did not know of, thank you!

Kind regards john