I need to replace the CPU in a Dell Dimension 4400. The socket is "mPGA 478B". I am wondering what CPU's will work in this and what speed it can handle up to if anyone knows. Here is what the bad CPU says on the back of it: intel pentium 4 1.6GHZ/256/400/1.75V SL5VH MALAY L209A952-2371 INTEL '01 I have been seeing CPU's that look just like mine, but they say "1.6A GHZ". What is the "A" and will that work in mine? I really gotta get this fixed bad. Thanks in advance!!

Why do you have to replace the CPU? Are your sure that's the problem? It's pretty difficult to fry a P4....

i put a working CPU in the mboard, and worked fine. I put the dead CPU in a working mboard, and wouldn't fire up. I hope the mboard won't fry the new CPU io get after a while. I forgot to ask above if a celeron will work in it since they are the same socket.

Of course it will work. Expert™

well, I'm on the Micro Center website now, and I see 2 that are in stock in the store near me. The first two on this page: http://microcenter.com/search_results_e_compare.phtml?category_title=System+Boards+%2F+Microprocessors&subcategory_title=Intel%AE+Processors+%2F+Upgrades&search_id=290bb543e864ef6ff261b1f826d6b187&sort_by=product.retail&manufacturer_title=Intel+Corporation that are $79.99. One is a 1.8 Celeron and one is a 2.4 Celeron. I would much rather get the faster one since it's the same price, but how would I know if my mboard would handle it?

motherboard has a socket 478 interface celerons and p4's will work...but where you may be limited is the front side bus limitation of the motherboard/bios your motherboard may be limited to 400 mhz front side bus cpu's, if that's the case, i think you can get up to a 2.0 ghz P4 or a 2.7 ghz celeron,both with 400 mhz front side bus, but i rather stay away from celerons..that's up to you..celerons aren't as good as regular P4's ...what i'm not sure about is if a 2.7 celeron is better than a 2.0 P4 Abit NF7-s 2500+ @ 3200+ 512 Corsair XMS PC3200 128 meg Radeon 9800 Pro 2 X 36 GIG WD Raptors in RAID 0 3+ Mbps cable connection

well, I got the 2.4 Celeron from Micro Center last night, put it in, and it works great so far. I just hope the m-board doesn't fry it like it may have done to the last one. Kinda sux now that I have this 1.6P4 chip sittin' here w/ nuttin to do w/. Oh well... What is it that make a Celeron crappy anyway?