Should I mix and match different size and speed RAM?

[Cyb]

Hi all,

I'm trying help a friend speed up their computer. Their PC has 512MB RAM and as I had 2 sticks spare RAM I decided to add it and see what happened. It all works fine, but I'm wondering as the RAM is difference speed and size, am I actually slowing it down uneccesarily?


These are the details of the PC. Any advice will be greatly appreciated.


Operating System
MS Windows XP Professional 32-bit SP2
CPU
AMD Athlon XP
Barton 0.13um Technology
RAM
1.3GB
Motherboard
K7S8X. (Socket-A)
Graphics
Default Monitor on RADEON 9200 SERIES
64MB RADEON 9200 SERIES (Connect3D)


Slot #1
Type DDR
Size 512 MBytes
Manufacturer
Max bandwidth PC2100 (133 MHz)
Serial number FFFFFFFF
Week/year 255 / 255
SPD Ext. EPP
JEDEC #2
JEDEC #1
Slot #2
Type DDR
Size 512 MBytes
Manufacturer
Max bandwidth PC3200 (200 MHz)
Part number DDR400--512M
SPD Ext. EPP
JEDEC #3
JEDEC #2
JEDEC #1
Slot #3
Type DDR
Size 256 MBytes
Manufacturer Melco
Max bandwidth PC2100 (133 MHz)
Part number
SPD Ext. EPP

[watercooled]

Should work fine just they will all run at the slowest speed (133MHz in this case)

[peterb]

Putting faster RAM in a machine won't (in itself) make it run faster - it is clocked by the PC, not the other way round, so to realise the benfit of faster RAM, you need a faster memory BUS speed. Similarly, putting slower RAM in won't necessariy slow it down, but if the memory bus is operating at a faster speed than the RAM is designed for, you will get increased memory error, or the machine won't work at all.

So in answer to your question, no, mixing the memory will not make any noticeable difference in performance, if it is working. However as a general rule, it is better to use memory of the same type, from the same mfr (and preferably from the same manufacturing batch - ie, buy it all at the same time) otherwise you may get problems with reliability, especially if you are operating at the design speed of the RAM.

[Cyb]

This is super fast help! Fast very much guys! I will leave the memory and see how thigns goes... friend probably won't noticed any difference

[peterb]

Glad to be of assistance . The additional RAM itself may speed up the response a bit, if only because it will reduce some of the hard drive access, but the degree of improvement will largely depend on the operating system (and the applications running on it) later versions of windows tend to be more efficient at using available RAM, as are Linux systems.

[watercooled]

More RAM generally helps if stuff is being swapped out to HDD a lot i.e. if the system is short on memory. If the HDD grinds away a lot when opening/switching between programs and if there are a fair few programs running at boot etc then more might RAM might help. 512MB seems to be about the minimum amount of RAM XP with SP3 can run with comfortably (the service packs do make the OS more RAM-hungry) so more should make a bit of a difference in this case IMO.