Samsung DDR2 533 oc to 838MHz @ 2.0v

[Timbosan]

Hi everyone, ive been out of the loop for a few months, and i just have my new system together. Specs:

CPU = e6300
Ram = samsung DDR2 533, 1.8v, 4-4-4-12
MOBO = Asus P5B vanilla BIOS 1402

I have overclocked to 2.93GHz (419 x 7) @ 1.30 vcore (real). Droops to 1.26v under load. Max cpu temp 60*C.
I have the ram at 1:1, 5-6-6-15, 2.0v (838MHz)
Sisoft 2007 Ram Bandwidth is ~6600MB/s
SuperPi 1M = 19.8 seconds

If i raise the bus to 429 (DDR 858) system experiences occaisional instability.
I'd like to raise the ram voltage to 2.1v so i can get DDR 858MHz. Any advice on what my timings should be, or if 2.1v is safe for this ram?

[heikis]

2.1V should be safe, but it could happen that it wont help. it might even degrade your OC of ram. it all depends and you have to try it out for yourself.
for ddr2-858 you should first set your latencies to CL5-5-5-5 and then start lowering and testing.

[Neon Biker]

You really shouldn't have gone for a 7x multi CPU + crappy RAM + intel chipset.

I just bought myself a pair of 1GB Samsung OEM DDR2-667 just because they were dirt-cheap, but I'm gonna match them with an E4300, so I really won't need more than 350-400MHz out of them.

[Timbosan]

heikis - are you sure about a Tras of 5? at 533 Tras = 12.
neon - i chose the e6300 for overclocking, and cos i couldnt justify anything more expensive. I also have some corsair XMS2 DDR2-800 for it, im just trying to get the most out of the 533 for fun.

[heikis]

sorry. my bad. 5-5-5-12 should be chosen

[Timbosan]

Cheers mate. The data sheet says absolute maximum voltage = 2.3v so yeah i thought 2.1v would be ok too.

[Timbosan]

update - bench stable at 838MHz, 5-5-5-15-6-42-10-11-10-13 @ 2.1v, but crashes or locks up during gaming.
Gaming + bench stable at 828MHz 5-6-6-15-6-42-10-11-10-13 @ 2.1v
Time to move to the XMS2 DDR2-800 :)

[SuperStarr]

My Samsung 1GB 667Mhz (M3 CE6 chip's) modules goes up to 432Mhz (864Mhz) on 1.95V, latencies: 5-5-4-4-11 2T, MoBo: BIOSTAR NF4 AM2L.
But I have one "problem":
DDR goes to this freq. only with 667 divider, with 533 divider can't goes more than 333Mhz (667 Mhz) with 1T / 340Mhz (680Mhz) with 2T timing, no matter latencies or Voltage of DDR & CPU.
What can be reason? BIOS on MoBo? Can it be? Or is that CPU (S64 Manila 3000+) "fault" as I think?

BTW, this memory is "imune" to Voltage, can't gain higher freq. if raise more than (default on this MoBo) 1.95V...

[Timbosan]

Sounds like a chipset limitation. 533 divider would run NB at a tighter strap due to lower ram speed, and may be limiting the max speed. At 667 divider, the strap is looser, so can go higher. Maybe a vNB or vMCH mod would help you?

[SuperStarr]

Won't help raising vNB, i try it from 1.550V (def.) to 1.7V (max.), results are same, won't boot if set more than 275Mhz FSB with divider 533 or 400.
I will try with different RAM, plan to buy Hynix Y5, if "problem" with divider remain, than I will change S64 for some "Brisby" :), I hope it will bi "jack point" combination! :)

Best regards!