Whats a good speed for 9800 hynix memory?

Ok guys, Im still a little new at ocing graphics cards and dont know all the information I need. First off I have a Sapphire Radeon 9800 Pro 256 with an r360 core and hynix 2.5ns memory. I currently have atitool but I have heard that it isnt a great program to use for clocking memory because some have had it burn up thier memory. I have used it to find my max clock which is 428, i currently have it bumped down to 420 however. I have every intention of flashing the bios to an xt, and I have a Thermaltake Giant II cooler on it.

Prior to the overclock my machine which is listed below would get around 5700 on 3dmark03, now with the overclock of my card to 417 367 i am only getting around 5820? To me this makes no sense. When I first got my card I wasnt happy with the 5700 and I remember overclocking it to 405 and the memory I dont remember where, however I got 6100.

What my question is, what would be a good memory speed that my card should have the ability to reach? Second, is it worth the investment to get memory sinks if I can only have them on one side of the board?(chip side) The backside of the giant doesnt allow room for the other 4. Am i asking too much here for a 6000 on 03? If anybody is willing to help me I will be grateful.

Thanks,

WheaT

if you push up the sppeds to far then you will see a drop in your score, the key is finding the peak

i have a 128mb saphire 9800pro with the r360 core and hynix mem(flashed to xt), i added some home made ram sinks and it did seem to give me an extra 10 or so mhz, on the core i have a cpu cooler from an old comp and it works great, at the moment my core is ok at about 460 and my mem seems stable at 385 ish although im volt modding it on tuesday when my local supplier gets the variable resistors i ordered,

i have yet to run 2k3 as i lost my cdr with it on and i keep putting off downloading it again (180mb on 512k broad band will take ages )

in 2k1 i get 19650

here is a pic of my card

http://www.ocforums.com/attachment.php?attachmentid=30396&stc=1

i just downloaded 2k3 and my first score was 6893

http://service.futuremark.com/compare?2k3=2610482

i hope to get well over 7k after i have a play around