well, the best way of gathering that information is if you measure the available space with a ruler or something, and compare with the GPU you are looking for Dimensions, but i don't think that is the problem, see, those pre-build computers always come with specs for optimum performance for the current hardware, and because of that they use normally use a Power Supply Unit that will fit the need only, so the problem is 300W psu (the default one in that model) isn't safe for any good mid-spec card, normally they require at least a 400w psu from a good brand, so the point is, do you have the money to exchange PSU and GPU? if you are aware of that, than you can measure spaces on the case, it is a mini tower so probably you will need a very good cable management to fit a big gpu there, best option is going for the gpus with lowest profiles since they are smaller to fit on smaller cases, also make sure a good PSU will fit there.
if you give us a budget we can help you finding good options of PSU/GPU match for that machine. also what is your monitor resolution, and for what you want the gpu? gaming? if yes what games?
Case Size specifications:
Height: 36.8 cm (14.4 inches)
Width: 16.5 cm (6.4 inches)
Depth: 38.9 cm (15.3 inches)
Weight: 8 Kg (17.6 lbs) - without packaging
well but fit isn't really a problem, if something don't fit there, you can always change your case, or even assembly components out of it.
I know this is a really old thread but I spent ages trying to find help with this.
I have installed a Gigabyte Nvidea GT630 2Gb grapics card on my HP p6-2065uk.
It is now a really good setup with the i7 processor and faster graphics.
Only problem with the p6-2065uk is that it will disable the onboard graphics automatically when it detects a card in the PCIe slot. So when you boot up you get a blank screen although Windose 7 loads OK (you can hear the audio tarah when it starts). This causes a problem trying to load the drivers from the CD.
I solved it by loading Google Chrome remote desktop on my computer and an old Dell PC so I could access my HP PC and view it's desktop. Connect the 2 PCs through the remote desktop and load the drivers.
It improved my Windose performance from 3.5 to 7! The improvement over the on-board graphics is astounding together with the i7 processor.
I also increased the memory from 4Gb to 8Gb and replaced the power supply with a Corsair CX430 as the graphics card needs more power the existing supply is only 300w.
Hope that helps some poor soul looking for an answer.