775 Woes

[OptyTrooper]

I have a P5K Pro paired with a E6550 and some G.Skill 1066. The problem is if I go over 533/1066 even by 1 it won't post. I have tried 333 and 400 strap with the same results. Is this a quirk of 775 and DDR2 and/or FSB or P35 chipset. Odd thing is if I overclock just the RAM it will post @ 1105 no issue.

 

[EarthDog]

FSB wall is the first thing I can think of...

 

[OptyTrooper]

FSB wall is the first thing I can think of...

That's what I was afraid of. Hopfully it's just a hole ad not a solid wall I'll try tweaking the PCI-e frequency I've heard that helps sometimes.

 

[OptyTrooper]

Just confirmed it's not a wall just posted @ 560 w/E8400. Maybe the E6550 just doesn't have any more in it.

 

[freeagent]

I'm surprised you got 560 out of p35, that's pretty good. I got about 540 with my p5k deluxe and e8600. Sounds like the 6550 is done.

 

[OptyTrooper]

Yeah these are not the best boards. Got a Maximus Formula coming soon!

 

[EarthDog]

Just confirmed it's not a wall just posted @ 560 w/E8400. Maybe the E6550 just doesn't have any more in it.

Its not a board wall... you just proved that. May be a CPU limit though. You didn't test with the same CPU.

 

[Tech Tweaker]

I suspect it's the CPU, some just don't like running with high memory speeds.

Could be the board as well though.

Edit: guess it was the CPU, didn't read the whole thread.

 

[RJARRRPCGP]

Looks like 3.7 is the limit for the cores on the E6550.....

I would think that's nothing for a Wolfdale, OTOH. Looks like Conroe is going the way of T. Rex!

 

[EarthDog]

There are plenty that go over that on air. It is not a 'hard' limit. Then, add DI/SS/LN2 on top and ti gets A LOT higher.

The problem is with the multi being so low you run into FSB limits on the board.

 

[Woomack]

If you can't pass some FSB on air then sub 0 won't help much. Older C2D or these with low ratios have usually low FSB wall. Most of E2xxx series or E6300/6400 that I was testing couldn't make more than 450MHz regardless of used cooling or voltage. Q9400 was also really bad.
Much better chance on high FSB is with Wolfdales E8200/8400/8500/8600. Most of the Conroe are generally hitting max clocks below 4GHz.

P5K Pro should reach 600FSB. I have P5K WS which is worse and has voltage limits on nearly everything and I can make on it ~550-580FSB.

There is one more thing. Memory on some boards is running above 1200 but when FSB:Mem = 1:1 then you may stop at ~550FSB running at highest CPU ratio. I had that with my last E8500. Max CPU ratio and 1:1 strap = max 570FSB while on low CPU ratio I could make 620MHz. On other straps memory was going up to ~1300.

 

[freeagent]

If you can find an old Conroe (first gen) it'll clock high for fsb, or it should.. I have one of those newer Philippines chips and it's junk.

 

[EarthDog]

Is there a slow mode on that board? Perhaps that will get you further...

 

[freeagent]

No slow mode.

 

[RJARRRPCGP]

The problem is with the multi being so low you run into FSB limits on the board.

QFT. (Especially with Q8200 or the like) But, it looks a lot like that one has a wall at 3.7 .