I made an incredibly stupid purchase around November 2008, and bought myself a Dell XPS 420 costing me around £1300 with screen, speakers and some gaming gear.
In terms of the computer, i soon came to realise that it was really not worth it.
Here are the hardware specs:
ATI Radeon 3870x2 GPU 1gb
750gb Hard drive.
XFI Xtream gamer soundcard.
I bought a bunch of hardware peripherals along with this, but i'm more than fine with them.
Ideally i'm looking at upgrading my RAM to a faster speed, since it's currently only 667mhz at the moment.
However the main issue I'm haping is upgrading the graphics card.
Ideally i want a 4870 x2. However i'm pretty sure my PSU will not be able to handle this, or will it?
If not, any recommendation on a new PSU?
I'm also thinking about overclocking, however currently i'm pretty sure that the stock stuff dell has given me is not any good for this. Again, any ideas?
Also i'm pretty fed up of the locked up dell bios, so i'm considering even changing the motherboard.
Any ideas to what i should do?
I'm rather confused since I know how a PC works in theory, yet i've never reallyd one anything more than change RAM.
With the locked down Dell BIOS, there's not much you'll be able to do, as far as overclocking goes. If you decide to upgrade the motherboard, then you'll want to look at RAM, once you've chosen a motherboard.
As long as the case has the room, yes. The 5870 is a pretty long card.
No, you don't have to upgrade the RAM, but it needs to be compatible with whatever motherboard you choose. If your current RAM is supported, you can stick with it. If you've got the $$, it's a good idea to upgrade though.
The CPU upgrade can be costly. If it suits your needs, there's no need to upgrade. The q9400 is a decent CPU.
Keep an eye on your temps. If they are getting high, then yes, you'll want to look at some cooling options.
It is possible, but it's not recommended to crossfire different graphics cards. There's a lot of difference between your two cards specifically, so I think you would have even more trouble than others. Here's an article that deals with this. http://www.legitreviews.com/article/663/1/
The 5870 is ~11 inches long. If you're thinking of spending that kind of $$, it's worth measuring to see if you have enough space. Keep in mind you may need to run cables around it.
Personally, I'd be extremely hesitant to put a 5870 in that case. The 420 uses a BTX motherboard and a specialized cooling hood. The 5870 would likely fit but the fan on the card would be partially obstructed by the hood itself which is going to limit its effectiveness. This coupled with the fact that there really isn't much in the way of airflow in there to begin with and I'd be concerned that you are going to have potential heat related issues that will ultimately start affecting components. If you decide to go this route, you will definitely need a new PSU as the stock supply on those boxes is a 375.
You may want to consider the merits of putting together a new system. The case doesn't lend itself well to upgrading and with the BTX motherboard you aren't going to be able to just transplant the components into another one.
I've added the link to Dell's site for this particular unit. One of the images there displays the computer with the side panel off. It'll give you an idea of what you'd be dealing with.
It definitely has a use. Those cases are designed to funnel the air from the front fan directly through the hood to the heatsink and the processor itself. I would definitely not remove it unless you installed a new fan and/or heatsink for the processor itself and I don't know that the motherboard has the necessary attachment points for it.
As for the additional fans, every little bit helps. You really only have one place to put them unless you are willing to modify the case by cutting a hole in the side panel. I've seen folks do that with the XPS 410 which is very similar.
I'm not an expert on crossfire so I can't really speak to that. I can say that the 5870 alone would probably be more than enough for your GPU needs. It's a pretty beefy card.
As for pulling old components from the 420, if it was me, I'd harvest the HDD and the DVD drive. If you use the other components, you'll be limiting your potential upgrade path later as you'll again have to go out and purchase a new motherboard and RAM to support the CPU upgrade. Plus the older components can sometimes run at something of a premium because they aren't mass produced any longer and tend to be less available.