DDR RAM

[MWISimmer]

I currently have 512mb DDR333. Question is, can i change this to 400?
Is memory mobo dependent, or can i add, change speeds etc?
I bought base unit (specs below) last month, but want to upgrade to 1024 min (pref 400, but if 333 so be it.)
Trouble is, i'm EXTREMELY naiive about all this.
I presume i've got 2x 256 with 2 spare.. but i've got a conveniently placed warranty label which, if i open my case, renders it invalid.
To sum up, warranty aside, could i add 512mb 400 (256 x 2 extra) to run with my 512mb 333? Or do i need all RAM at the same speed, or would 1x stick of 512mb 333 be ok?
BTW
Factory re-work Advent T9201, bought on the cheap...

[4_Series_Scania]

I currently have 512mb DDR333. Question is, can i change this to 400?
Is memory mobo dependent, or can i add, change speeds etc?
I bought base unit (specs below) last month, but want to upgrade to 1024 min (pref 400, but if 333 so be it.)
Trouble is, i'm EXTREMELY naiive about all this.
I presume i've got 2x 256 with 2 spare.. but i've got a conveniently placed warranty label which, if i open my case, renders it invalid.
To sum up, warranty aside, could i add 512mb 400 (256 x 2 extra) to run with my 512mb 333? Or do i need all RAM at the same speed, or would 1x stick of 512mb 333 be ok?
BTW
Factory re-work Advent T9201, bought on the cheap...

If you add PC400 (3200) DDR to a P4 system with 333 RAM then the system will run at the speed of the slowest RAM stick installed.

You'll benefit from the extra RAM even if it runs at a slower speed to your existing 512MB as XP is certainly happier with 1GB rather than 512MB.

The best solution would be to get all of the RAM at the same speed, this would more than likely run "Dual Channel" giving a further speed boost.

Expect to pay

[MWISimmer]

Mr. Goat, thank you for your help & link.
I said i was naive, i actually have only 2 RAM capable of 2048.
I'm taking the plunge this weekend & installing 512mb PC3200 (Crucial), doubling my current setup..... First ever upgrade on my own.
And yes, my current RAM is PC3200.

[congo]

Hi Simmer,

You won't get the performance that PC is capable of unless you run the PC3200 in Dual Channel mode, thus eliminating the RAM bottleneck on the bus.

In fact, you may get slower performance by adding another ram module to your current Dual Channel configuration, (if in fact you have 2 x 256mb sticks in the correct Dual Channel slots), thus reducing your PC's actual bandwidth capacity.

You can download a wonderful little program called EVEREST to test your bandwidth for comparitive analysis between configurations. Everest is a system info utility that looks exactly like Aida32, ( it may be the same for all I know), and it gives a very lot of useful info about your system. Basically, if the bandwidth goes down, the PC is slower, despite the amount of ram installed. ( I know it sounds wierd but it's true!)

I'm still a little confused about what you actually do have, but this is what you need................

2 x identical (or near identical) Ram modules of the same size and speed (preferably bought together from the same batch!).
Usually, 2 x 512mb modules are sufficient.
Quality RAM (not the bargain basement stuff!) is pretty much a requirement for high speed ram on dual channel setups.

These modules must be placed in the 2 "dual channel" Ram slots in order for the dual channel configuration to be enabled. As far as I'm aware, no other RAM configuration on an 865PE chipset will work in dual channel mode.

Beware buying more, and getting less.