Extending the life of a Pentium D desktop via a processor swap?

June 5, 2008 11:44 AM

Can I extend the life of my aging Dell XPS desktop by means of a processor swap? Details within.

I have a late-2005-era Dell XPS 400 with a 3.2GHz Pentium D and a Dell-branded mainboard featuring (according to CPU-Z) an Intel i945P/PL/G/GZ chipset.

Is it possible to swap the Pentium D for a Core 2 Duo? If it's possible, is it also a sensible thing to do? I'm trying to avoid shelling out for a new desktop for another 1.5 years or so.

posted by killdevil to computers & internet (13 comments total)

More specifically, the processor currently installed is an Intel Pentium D 840 (Socket 775 LGA).
posted by killdevil at 11:47 AM on June 5, 2008

Is there a reason your current desktop is not cutting it? 3.2Ghz is plenty fast for most tasks; if the system is sluggish, a wipe and reinstall will get it back up to speed.

(I don't know if you can swap out the chips)
posted by PercussivePaul at 11:50 AM on June 5, 2008

Is there a reason your current desktop is not cutting it?

I play a couple of games that I think could benefit from an updated processor, if the upgrade cost isn't overwhelming. I've already swapped out the GPU.
posted by killdevil at 11:53 AM on June 5, 2008

No. you can't do it. Old P4 LGA775 motherboards are incompatible with Core and Core 2 chips.

On the plus side, new big-brand LGA775 motherboards are pretty cheap, and if you get one that takes DDR2 RAM, you'll find that even 4Gb of memory (all of which you will probably not be able to use) will cost you amazingly little. You'd see a nice speed boost even if you got equipped this new mobo with a bargain-basement Pentium Dual-Core CPU (and those chips are VERY overclockable); lower-end Core 2 Duos and Quads are also rather inexpensive these days.

Note that the above does not constitute a guarantee that you'd be able to shoehorn the above into your old Dell's case. If I were you I'd keep the Dell untouched to use as a second system or sell, and make the upgrade a whole new PC.

I appreciate that there's a significant conceptual and budgetary distance between "new CPU" and "whole new computer". But that's really what I'd be saving up for, if I were in your situation.
posted by dansdata at 11:56 AM on June 5, 2008

(If you're going to buy a whole new computer, you could of course get an AMD system instead of an Intel one. Intel currently have the value edge, though, especially if you want to overclock.)
posted by dansdata at 12:01 PM on June 5, 2008

A 3.2 GHz Pentium D really isn't all that slow. Unless you're going full AA and beyond 1280x1020, you shouldn't be that CPU bound.
Out of curiosity, what GPU do you use now?

Old P4 LGA775 motherboards are incompatible with Core and Core 2 chips.

According to plenty of MB specs, the socket 775 will work with both Pentium D and C2D. For instance.
posted by jmd82 at 12:05 PM on June 5, 2008

According to plenty of MB specs, the socket 775 will work with both Pentium D and C2D.

Yes, but those aren't old Socket 775 boards; they're ones that're on sale now.

All LGA775 sockets are mechanically compatible with any LGA775 chip, but that doesn't mean it'll actually work.
posted by dansdata at 12:34 PM on June 5, 2008

Unless you're going full AA and beyond 1280x1020, you shouldn't be that CPU bound.
Out of curiosity, what GPU do you use now?

I'm driving a 1920x1200 flat panel with an 8800 GTX.

On the plus side, new big-brand LGA775 motherboards are pretty cheap, and if you get one that takes DDR2 RAM, you'll find that even 4Gb of memory (all of which you will probably not be able to use) will cost you amazingly little.

If I were to swap a new mainboard into the Dell, which ones in particular should I be looking at? I'd need something compatible with my current memory, etc. If this option is cheap enough, the motherboard plus the new processor might be a reasonable solution. I should note that the XPS 400 has a nice big case.
posted by killdevil at 12:47 PM on June 5, 2008

You should double check to see if thats a full ATX size board or one of those mini ATX boards. Dells of that vintage used those mini boards which are difficult to find.
posted by damn dirty ape at 1:00 PM on June 5, 2008

If I were to swap a new mainboard into the Dell, which ones in particular should I be looking at?

I don't know - sorry. Dells these days are pretty close to standard (not long ago they had wilfully non-standard power supplies and similar BS to lock you into Dell And Nobody But Dell for support), but I know no more about the deal for your particular computer than you can find out for yourself with a Google search.

Perhaps you'd be able to swap an Abit/Asus/Gigabyte/MSI board into your current computer with no trouble at all (beyond the usual possibility of frying the new hardware because you took inadequate anti-static precautions). But I really don't know.
posted by dansdata at 1:01 PM on June 5, 2008

I had a machine like that. It was a custom mainboard, so it couldn't be replaced (new ones wouldn't fit in the case) and it had a Pentium D805, and the best I could get out of an upgrade was swapping in a E6750 Core2 Duo.
posted by blue_beetle at 1:25 PM on June 5, 2008

Id also say this whole endeavor is probably a good example of the laws of diminishing returns. Even if that 775 slot accepts a C2D, you still have a slow bus, slow drive, slow memory, etc. Id do motherboard replacement at the minumum but at that price point you might as well start saving up for a new machine.

I have a lot of desktops at work with Pentium Ds and HTs of around that speed and also more than a few C2Ds and X2 machines and honestly cant tell the difference between them. FWIW, I can always spot a slow drive. Unless youre doing tasks that are processor bound then you probably wont notice anything other than better multimedia encoding times, better virtual machine performance, and perhaps a little extra springiness now and again.

Most people (average users) are memory bound. So if that box only has 512 megs, then your money is better spent moving up to 2 gigs and even a clean windows install to knock out all the cruft, or at least a serious cleanup. Toss in a new fast drive and you'll get a slight performance boost and the peace of mind of knowing your stuff isnt on a drive manufacturered 4 years ago.
posted by damn dirty ape at 1:47 PM on June 5, 2008

Try calling Dell, I'm sure they will know.

Also, you can get cheap Core2 supported motherboards for <$50. Fry's often has a E2180 (2.0ghz) + Mobo for $99.
posted by wongcorgi at 2:14 PM on June 5, 2008