C2D 6420 vs 6750

[slippyjim]

Hiya

I had a 6420 but then I had the chance to swap it for a 6750 for free so I did. But the 6750 hasn't really OC'd much more than the 6420, is this normal?

I had the 6420 @ 3.4GHz
the 6750 is @ 3.6GHz

Gigabyte P35-S3 (latest BIOS)
2 * 1GB OCZ DDR2 1066MHz RAM

For some reason I didn't expect it to OC as well but I thought with the 6750 starting 0.5GHz ahead I would have done better.

Cheers,
Steve

 

[Gunther]

We'll yes, they are in principle the same ship E6750 is just an Overclocked E6420 with a different max temp. And not every chip will clock the same, it's pure luck to have an extremely high clocking cpu. Everything above stock is lucky draw

 

[simonnance]

We'll yes, they are in principle the same ship E6750 is just an Overclocked E6420 with a different max temp.

Higher FSB on the xx50 over the xx20 too though. 1333 vs 1066.... this can cut both ways, the 1333 might get higher FSB speeds, but the build in multi is less so you need to hit higher FSBs.

333x8 = 2666Mhz (E6750)
266x8= 2128Mhz (E6420)

Same multi then. Same cache too.

Some people have reported better OCing on the xx50s, but tbh its very chip dependant. TBH unless you are going for a Q6600 its almost better to go for one of the E21xx range and just clock the nuts off the chip, but as you already have the chip then all you can do is try it and see.

As with all overclocking "your mileage may vary"

 

[slippyjim]

So I've probably done alright to actually get a few more MHz out of it so far.

Originally I wondered about the 21xx vs 6xxx and eventually I decided I wanted the extra cache. Toms hardware recently did an article on this and it looks like cache does make a difference, not really sure if its worth the extra money, but what the heck!!!

thanks for the replies

 

[Rab]

my 6750 is stable @ 3.6.
have had it max stable 3850, but volts where to much for liking.
there was a post here not long ago that the "A" steppings where not good @ o/c
as all said above, sometimes just pure luck to get a good o/c or bad luck & get a bad 1

35 % overclocked aint that bad , eps when it was for free

 

[slippyjim]

thats just reminded me, with my mobo as soon as I increase the CPU voltage (even the smallest increment) it wont even boot into Windows, it POSTS's but thats it. It did the same with the 6420 and 6750

I'm at 3.62GHz with my 6750 at the mo

 

[Davey D]

Ive got my 6750 running at 3.2Ghz. all i had to do is increase the FSB to 400. the voltage didnt need any tweaking. it is orthos stable for a day, which is the longest ive let it run for.
im not going to push it any higher, as its in a small FF case, and i dont want things to get too toasty in there

 

[slippyjim]

Mine isnt even in a case!!

The one I wanted wasn't in stock at the time and 5 months later I've still got everything laid out on my desk!!

My 6750 has cruised up to 3.62GHz, it was Orthos stable for a couple of hours before I stopped it and it has been running ever since which is about 5 or 6 days