New PSU vs. Old PSU - Are they different sizes?

Question

I want to get a new PSU soon, and I want to get this one. Problem is that I'm not sure if it will fit in my PC. My PC is a HP a6500f and it comes with a stock 250W PSU. From tinyurl.com/ncz2vl it said that its an ATX PSU (I think).

I measured my current OEM PSU from HP, and it's:

15cm x 14cm x 8.5cm

The new PSU from Newegg has these dimensions (once converted into cm):

23.4cm x 22.1cm x 9.91cm

Later on I want to add either a 8500GT or a 9500GT

Will the new PSU fit, or do I have to get a different one?

Answer 1

There is a surprising amount of variability in PSU sizes in my experience, even for the "standard" PSU formats. So be careful, measure, and look at the HxWxD measurements for the model you plan to buy!

• ATX: 6x3.5x5.5", HxWxD. Most common. Uses 4 mounting screws.
• Mini-ATX: 5x3.5x5", HxWxD. Rare size. Uses 4 mounting screws. Can be used in a regular ATX case, but often not the other way around.
• MicroATX: 5x3x4", HxWxD. Use 3 mounting screws. Not interchangeable with ATX or miniATX.
• Flex ATX: Even smaller than Micro ATX. Various sizes according to case specs; often not interchangeable.

Answer 2

From my experience with an OEM HP computer, they usually come with unusually small PSUs (in part to cut costs, I suppose). I had to replace the PSU on my HP because it died, and I wasn't able to find any that were as small as the original. However, the newer, larger one I purchased (standard size) did fit into the slot; the only issue is, I had to take the computer nearly all the way apart and pull out the CD drives in order to make installing it possible. It made the PSU/CD drive cable/CD drive clearance really tight, but it worked.