Reall bad E6400 o/c results

[Goi]

Hi, I just helped my friend build a PC yesterday with the following specs:
C2D E6400 w/default HSF
Asus P5B
2x1GB Twinmos DDR2-667 memory
ATI X1950Pro
Hitachi 320GB SATA2 HDD
Samsung 18X DVD burner
Seventeam 460EAG PSU

After setting it up I decided to play around with mild overclocking(stock voltages/memory timings/etc) since I've read really good things about the E6400 and overclocking. The highest FSB I got was only 280, with 290 and above failing to even POST. Though I was using stock cooling and voltages, I was under the impression that I should at least be able to hit 300? The memory shouldn't be a problem since it's still running at below 667MHz anyway, so what else might be the problem?

 

[cmdrdredd]

Originally posted by: Goi
Hi, I just helped my friend build a PC yesterday with the following specs:
C2D E6400 w/default HSF
Asus P5B
2x1GB Twinmos DDR2-667 memory
ATI X1950Pro
Hitachi 320GB SATA2 HDD
Samsung 18X DVD burner
Seventeam 460EAG PSU

After setting it up I decided to play around with mild overclocking(stock voltages/memory timings/etc) since I've read really good things about the E6400 and overclocking. The highest FSB I got was only 280, with 290 and above failing to even POST. Though I was using stock cooling and voltages, I was under the impression that I should at least be able to hit 300? The memory shouldn't be a problem since it's still running at below 667MHz anyway, so what else might be the problem?

*sigh* this is about the 5,000,000,000,000,000th time I've said this. SKIP EVERYTHING BEFORE 400MHZ FSB!

It would probably start right up at 400Mhz FSB. You can drop the Multi down to 7x and run 2.8Ghz vs the usual 3.2Ghz at 8x multi. The memory would have to run at DDR2-800 and it may at cas5

 

[Goi]

I'm sorry but why? Is there something about the mobo or chipset that makes it have issues anything between 280-400MHz?

 

[cmdrdredd]

Originally posted by: Goi
I'm sorry but why? Is there something about the mobo or chipset that makes it have issues anything between 280-400MHz?

specifically I have no idea what happens, but something makes it really hard to work with between 267 and near 400. Some people can boot at 267-270 then have to jump to 305 and it will go from 305-330 before it starts having issues again. It's strange...I just tell everyone to jump to 400Mhz and forget it.

My P5B-D will not boot between 275 and 300 but will do 305-350 and then I need to go to 392 before it's stable again. I can boot everything between 400Mhz and 523Mhz and it works (but my CPU limits what the board can actually do.)

I didn't mean to seem like I was yelling at you in my first reply. I just would have thought this was common knowledge now about the FSB holes and the P5B.

 

[myocardia]

Originally posted by: Goi
I'm sorry but why? Is there something about the mobo or chipset that makes it have issues anything between 280-400MHz?

Yeah, it's the chipset, in a way. Intel uses memory "straps", and although it works, it works pretty screwy. Here's some info on memory straps: link.

 

[Goi]

Hmm ok, but 400MHz seems like a stretch. I was hoping to reach about 350MHz and call it a day, since it's for my friend and I won't be around to help him out if it's unstable. Besides, he's using the stock hsf and stock voltages and DDR2-667 memory.

 

[cmdrdredd]

Originally posted by: Goi
Hmm ok, but 400MHz seems like a stretch. I was hoping to reach about 350MHz and call it a day, since it's for my friend and I won't be around to help him out if it's unstable. Besides, he's using the stock hsf and stock voltages and DDR2-667 memory.

run the memory at 5-5-5-15 and it should do 800Mhz. 400Mhz FSB is nothing and if you run the 7x multi it will be 2.8Ghz which is doable.

 

[Goi]

OK, I'll try that the next time I'm over at his place then.

 

[n7]

Have you set the RAM ratio to 1:1 aka DDR2-533?

You should be able to get to around 350 before having to jump to 401.

Make sure RAM timings are loose:
Run 5-5-5-15-6-42-10-10-10-10 @ a bump above rated vdimm.

 

[twjr]

Just had a query about these memory straps. As Intel is intending on releasing 1333MHz C2D's at some point, shouldn't there also be another stable area around the 333MHz FSB mark?

 

[Goi]

I haven't had a chance to meet my friend again, with it being the holiday season.