Pentium 4 571 (3.8GHz), 64-bit, Prescott, FSB800, L2 Cache 1MB

-OR-

Pentium D 950 (3.4GHz ,95w), 65nm, Presler, Dual Core, FSB800, L2 Cache 2x2MB

Both are compatible with my Motherboard... I have the first one listed.
I was just curious if I would gain "SPEED" if purchasing the Pentium D.

If that's the choice then go for the dual core Pentium D.
P4 are being phased out.

Couple this with a shed load of RAM (2Gb) and you're good to go.

Actually, in many benchmarks, the AMD X2 performs much better than both the Intel Pentium D and the Pentium 4!

You can buy a dual core AMD Athlon X2 3800+ for less than $90, and since it has much higher bus speeds, it will perform much better than Intel's CPUs.

Plus, its also really cheap!!

Would an AMD chip fit into his already purchased motherboard though?

Npoe ;)

A good motherboard that I use is a Asus M2N - E motherboard, which uses the AM2 Socket, and its quite readily available for overclocking, and I bought mine for approximately $115 USD.

My whole system (including 19 inch Widescreen LCD) cost less than $1000! AMD parts and compatible motherboards are much cheaper than intel's !

However, even if you pruchase a new Mobo with an AMD chip, you might find it costs less or about the same as buying a pentium D

Thanks for the responses... I'm not really looking forward to buying a new mobo.. if I'm going to do that I'll go all the way.. but not at this time.

It all started by that I have Windows Vista and they have that computer ranking system... everything I have is a 5.0 through 5.9 EXCEPT my 3.8 Ghz processor which ranked 4.5 and my memory pc3200 which ranked 4.4 BTW... 5.9 being the highest.

The reason I asked about the pentium D 950 I can get it for the same price that I got my pentium 4 3.8 ghz which is around 175 dollars.
I got another response from a "cpu" expert that the 3.8 cpu is king over the pentium D.

Instead of buying new stuff, have you tried tweaking the memory timings in the BIOS? Assuming you are using a MB with overclocking features. There are tons of tweaking guides on the 'net to help you out.

Your processor dual core has two cores instead of having only one with the other model. You should definitely choose the dual core.
The question was about the two models and not other models and brands, we all know that AMD is cheaper than Intel but the best processor of all times is Intel, obviusly the top of the top from Intel vrs the top of the top of AMD, Intel always wins.