Yes, but his old stick was 533mhz, so if he gets 800mhz, it will be wasted money.
Well, the DDR2800 is about 2 to 7 dollars more expensive and all come with heat spreaders; so I don't think it's really wasted.
But it's better to buy an 533 new stick and put it together with the other, instead of taking the old one out and leaving a new 800mhz in is spot ,right?
Well, are you assuming that you need to remove the old module in order to put in the 800MHz? Cause you can add either the 800 or 533MHz module. Cause I'm guessing that you have one stick on the motherboard currently, and 1.5GB of RAM is could be better than the 2136MB/s increase in bandwidth.
Down clocking the 800MHz module actually means that you could decrease the CAS latency and it would allow you to get better RAM if you ever wanted to; or if you got a new motherboard, etc.
If you add a 533MHz module, then nothing happens except an increase in memory. If you add a 800MHz module, then that particular module will be slowed down to 533MHz, so it does the exact same thing as if you added the 533MHz module. And if you add a 800MHz module and remove the old 533MHz module, then you increase the bandwidth from 4264MB/s to 6400MB/s. Which may make a difference, but most of the time more RAM is better than an increase bandwidth, especially since your FSB only operates at 533MHz.
NOTE: These bandwidths are theoretical limitations assuming that your motherboard operates in single channel architecture.
well, hm... I will just buy the 533mhz 1GB stick of Ram and put it together with the other one. Thanks a lot to everyone who helped in clearing out this stuff for me!:D
I recommend Corsair xms2, cheap and fast.
You can get a OCZ Platinum DDR2 800 2GB kit for $47 from newegg, which should clock down to the max speed supported by your mobo (533Mhz).
Also, if you can, try to match the latency (timings). Yours runs at 4-4-4-12 going lower is wasted money and going higher will slow your timings a bit as like the MHz speed, the timings used by the system default to the slowest (lower is faster in timings).
OK I'll do that. Thanks everyone :)