Hi i've been recently upgrading my PC and so far the only two things i have not yet to upgrade are my Motherboard which i do not and do not see a point in doing, But my memory i was just ignoring for quite sometime and didnt think it would be slowing my system down which on the other hand i do not notice but let see if yall think my memory is slowing other hardware down heres my pc specs:

Asus M2N4-SLI nForce 4
AMD AM2 X2 5000+ BE
eVGA 9600GT Superclocked
Seagate 250gb Sata 3Gb/s
Heres the Catch
Kingston DDR2 533 (PC2 4200) 512 x 4

So if you noticed already my ram is only running at 533 when my mobo can support memory up to DDR2 800 speeds is this slowing down the rest of my system? Thinking about upgrading here very soon if so. Thanks for your help.

You will certainly gain from a memory speed upgrade to 800, Corsair matched XMS2 set is cheap, go with 2x1 GB sticks, or 2x2 GB if you dont overclock the fsb. At the same time if it aint broke... wait for your next board upgrade.

Yes indeed, and unlike its rivals, the Intel processors, the memory plays more important role with AMD series. This is due to the Hypertransport technology IMO. I don't really understand of this HT yet, eventhough I did some thorough researchs on it. So don't ask me why and what

Anyhow, here is the link from anand that might be useful: http://www.anandtech.com/memory/sh [...] i=2800&p=7

Just read it, and decide yourself. I can say that the difference is 'noticable', not that much, but noticable. Unlike with Intel C2D: there are no noticable difference with DDR2-533 or DDR2-800.

For any AM2 processor, you should go with DDR2-800 or faster.
The calculation is not like with Intel.
You divide the CPU multiplier by 2, round it up. Divide that by the clock.
13/2=7
2600/7=372 which is about 400.
So you buy DDR2-800.