Hynix D5 - Poor bandwidth efficiency?

I just installed a stick of 512mb Kingmax PC4000 TSOP w/ Hynix D5 modules, and started the testing at 260HTT 1:1, using 3-4-4-8 (SPD timings) w/ 2T command. I have the "Performance" mode in the BIOS enabled. Tried using 1T command, and Windows will not boot.

After running a benchmark in Sandra I was horribly disappointed, and only achieved a measly score of 3400MB/s. WTF? Memory bandwidth efficiency was quoted at 82% for both Integer and Float, which is lower than what I am used to.

Is there any way to get more juice out of these? I'm not exactly sure what these chips are capable of, but my board can do over 300HTT stable. What are the recommended settings to get the most out of this memory? Any help would be appreciated.

A64 banwith efficency/overall bandwith fall off almost terribly when 2t timing is used, w/ A64, if at all possible, use 1T timing, you effecincy should come u into the 94-97% range, and it is possible to gain 300-500+mbs bandwith.

as long as you have 1x512 you should be able to use 1t timing. a64 usually cant use 1t timing w/ 2x512 w/ ram speed over 230ish mhz........

EDIT:also whats the highest stock Vdimm for you mobo?

it is possible that you might be able to run 2.5-4-4-8 but most likely you will get best results w/ 3-4-4-8

try disabliling performance mode, and using 1t, also try moving ram to a different slot to see if you can achive 1t timing and be able to boot....

also possibly a different bios..?

Anytime I use 1T the system bails when booting XP, it will go past the windows logo, and then restart. I tried setting "system performance" to normal in the BIOS, still no go. VDimm is set to the max setting, 2.8v, which the damn board undervolts to around 2.7-2.75.

I think there is still more overhead for increased FSB. I am about to break 3500mb/s now using 266HTT, 3-4-4-11 2T, still 82% efficiency. I am amazed at the FSB potential of these hynix chips, too bad for such terrible timings.

Two questions remain:

A) In the old Athlon XP boards, a high Tras was recommended, I believe 11 was the general concensus for best performance. Does the same hold true for A64? I tried a couple different settings, but could not discern any noticable difference.

B) What in the world does the "system performance" setting in the BIOS do? It's options are merely "normal" and "fastest".

well the 11tras doesnt hold true for A64, i have tested tras from 5-15, and 5 is the fastest followed by 6, etc....

im not inteirly sure what the performance opion means, but i feel that it has something to do w/ Dram drive strenght, but in not for sure, and im not totally sure what drive strenth is either.

also it could be bios presets of other ram timings like Bank Cycle timer(Tcr), Dram Idle timer, Row to Column(tRCD), bypasses and other things seen here....