What socket P CPU for upgrade?

[Azzyasi]

I have a Dell Vostro 860 with 1.86Ghz T1500 (dual-core Celeron), 2x1 GB ddr2, and GM965 chipset

I want to upgrade it a bit.
I found a relatively cheap T7500. How much better is than my T1500?
I'm lost in intel namings with T, P, and only found out about different sockets. And on all sites T1500 have only socket P and thus I'm looking on socket P CPU's
What is the order of performance based on their naming? T1500 is Merom based and T7500 is also merom or penryn. What is better merom? penryn? what series? T1500, T2xxx, T3xxx, T4xxx, T5xxx, T6xxx, T7xxx, T8xxx. T9xxx. (I know T9xxx are the leaders but cannot find any T9xxx on a decent price, actually cannot find it at all in stock.. so I'm on a sear a little below... T7500? T6600? T5xxx? T8xxx?)

what about the P series over T series.. i see that some of Pxxxx cpu's have socketP and it coult work I guess? those codes give me a headache.. I have a hint for desktops but for laptops I'm really confused)

I need it it for labview/matlab/autocad/catia and stuff like that, no games (solitaire/minesweeper doesn't count ).

I am forced to use windows xp 32-bit (because of other programs that won't run on x64, or vista or 7, plus I have license for win xp, not vista or 7. So cosidering this 32bit OS, will it have any sense to upgrade to 4gb ram from 2gb? (I think* it will see about 3gb maximum or even less)

*-based on my experience a normal desktop computer sees only 3.25GB, a SLI motherboard with vista x86 sees only 2.8GB. I think that laptop MB's are using lots of adresses for lot's of things (cd-drive, wi-fi, firewire, pcmcia, ethernet, touchpad, etc) and because of that less addresses to go to ram.

Anyway.

 

[WR2]

I am forced to use windows xp 32-bit (because of other programs that won't run on x64, or vista or 7, plus I have license for win xp, not vista or 7. So cosidering this 32bit OS, will it have any sense to upgrade to 4gb ram from 2gb? (I think* it will see about 3gb maximum or even less)

About 3.5GB is what should be available for Windows. But for XP 2GB should be enough.
You can always run a dual boot system when you have WinXP 32bit or Win7 64bit on the same computer.
You choose which one you want to use from a menu at bootup time.
How to Setup a Dual Boot Installation with Windows 7 and XP

Dell Vostro A840/A860 Service Manual: Remove/Replace the CPU

Passmark CPU benchmark scores:
http/www.cpubenchmark.net/cpu_list.php

Intel T1500 @ 1.86GHz = 992
Intel Core2 Duo T7500 @ 2.20GHz = 1272

 

[Azzyasi]

ok, but the question was: should I upgrade from t1500 (celeron, merom based) to t7500 (merom). Since I have 965chipset 800mhz fsb support, i'd go with newer cpu's.. is penryn better than merom? what penryn cpu's are with fsb 800 and with socket P ?

I realize t7500 is better than t1500 but what else I could upgrade to? I see there are some Pxxxx cpu's and apparently have socket P ; are those compatible?

 

[WR2]

That upgrade is almost like a move side ways. It's just barely enough of a change in performance to notice.
It will not make the laptop 'noticeably faster'.