Ive recently brought my old gaming rig back online to play the occasional game and do photo editing on.

She is, in most respects, slower than my laptop. As such I am seriously considering whether I can afford to upgrade in a meaningful way. Current spec is:

2x AthlonXP 1700+ DLT3C (remember those??), clocked at 1600Mhz.
Tyan Tiger MPX motherboard (hence the fairly pathetic OC)
2GB Crucial RegECC DDR266 RAM
NVidia Geforce 4 4200
~200GB total storage across 2 discs.
Enermax 431W PSU

All in a custom home made case, CPU and HDDs are watercooled and the main Rad fans (twin 120mm Papsts) blow over the motherboard to keep temps in general down.

I was thinking of perhaps getting a lowish end Core2Duo, fair to middling GFX card, good RAM and motherboard and probably a new PSU and taking advantage of the existing WC system to overclock some. After all, a Core2Duo produces rather less heat than either of the Palomino cored AthlonMPs this system was originally designed to cool (the DLT3Cs came later) so I figure I should be in for some reasonable speeds.

My basic problem is that Im so far out of the loop its not funny, and all the pages I can find on OCing Core2 chips are at least a year old.

Is Core2Duo the right way to go or are the low end A64X2s more overclockable? Not too worried about outright performance (as long as its significantly faster than 2x AthlonXP1900+ chips), just performance per pound when overclocked. Are there any cores/steppings/etc which I should look for/avoid?

What motherboards should I be looking at? or at least what chipsets, there seem to be a bewildering variety at the moment and Im lost.

Im thinking an SLI/Crossfire capable motherboard and a single mid range card to begin with, giving me an easy upgrade path for GFX if I want it.

Any and all advice welcome, I just want to figure out if I can afford an upgrade thats worth doing, then Ill think about actually doing it in maybe a month or so.

Intel has the edge over AMD for value for money by a large margin when overclocked  IMO

Wolfdales are really great chips have a look at this post I made about my Nephews E8200 http://www.tekforum.co.uk/posts/list/12170.page
My own E8400 isn't quite as good as his and tops out at 4Ghz and does Superpi in 11s but both of those are on pretty quite air, so there could be a bit more in them on water

Tekheads have the E8500 3.16GHz on special at the minute at only £119.85.

Abit IP-35PRO £96.35, while I have not used one myself I hear it is a great board for the price, of course you could spend double that and get a top of the line board but, there is only a few % in it from the P35.  

No matter what board you go for your going to need to address the chipset cooling seeing most rely on the air flow from the CPU cooler to remove it.
 Imnot up to date on water cooling so no idea how best to handle that? ...maybe a slow spinning 120mm fan might be enough?

I guess a 8800 GT would be your best bet for a good performing mid range card and can be picked up for about 80-90 quid from OCUK.
Have a look at the individual game scores in this review of a Radeon HD 4850 http://www.anandtech.com/video/showdoc.aspx?i=3341&p=1 to see how they perform in SLI.

You would need a new PSU as well if your going SLI, 800w is enough for the cards and would give you a overhead for overclocking, also you would need a new hard drive more than likely, as nearly all mobo's have only have 2 IDE connectors these days also it would blunt the performance quite a bit with such a old drive.

As shaun says, its e8x00 goodness all the way

thanks Chaps, Ive noticed that the E7200 also has a wolfdale core and is about £30 cheaper. Are these as overclockable as their big brothers? and does the 3MB cache vs 6MB really make that much difference?

The 3mb chips are about 10% slow in games and 5% slower overall than a 6mb chip.

Review here with more details: http://www.xbitlabs.com/articles/cpu/display/core2duo-e7200.html they hit nearly 4ghz on sensible voltage with it as well, looks like pretty good bang for the bucks!

thanks Shaun, I was looking for a review of this chip but couldnt find one for some reason. Its looking like a good candidate for water cooled fun and frolics

That Abit mobo looks pretty good on the face of it, but it supports CrossFire rather than SLi so I guess Im best off with an ATi card?

Im guessing that more or less anything available now will be quicker than my GF4 Ti4200 right? In which case I might go for something fairly cheap GFX wise to start with and upgrade later if I get back into gaming in a more serious way. At the moment the most demanding thing the system will need to do is Doom3.

Oh glad you noticed my noobie error before you bought anything  :whoops:

http://www.xtremesystems.org/forums/showthread.php?t=149024 another review of the board if you haven't seen it.

how about this for a graphics card

http://www.tekheads.co.uk/s/product?product=608619

a little slow perhaps but the 3650 seems to play most things on modest settings, and it is crossfire ready if I should need an upgrade in future.

Tbh I would try to strech to a 3850 http://www.tekheads.co.uk/s/product?product=609224  20 quid more but the benchmarks look alot better

true, Ill have to see how my finances look after I next get paid (early Sept). If I skimp on something itll be the GFX card but obviously I dont want to be imediately replacing it.

Who is good for PSUs these days, are Antec still basically top of the heap?

thanks for all your posts Shaun youve been most helpful

Yep Antec are still good, but so are CoolerMaster,  Corsair, OCZ and Silverstone those where the ones that got the most good reviews when I was considering if to go SLI a couple of months ago

Corsair look to be a good choice atm, they do well in most current level tests and are really quite efficient. Hopefully my VX550 should arrive on tuesday :mrgreen:
And as for CPU, wolfdales are excellent. Mine does 3.2gHz very easily on just 1.14v, would probably go further but I cba trying, saves gambling with the RAM.
Also, P45 chipsets are worth a look at. All the bonuses of P35, but with PCI-e 2.0 for extra graphics goodness. And most should manage a 1600mHz fsb without breaking a sweat.