920 Uncore more than dram x 2+2 ?

[pubem]

Hi,

We know that the default uncore is always 2x or 2x+ 1 or 2x+2.

But what if we raise it more than this ?

We must be under pqi of course.

Would be great to hear your experiences on this.

Here, on certain dram/uncore rates works, and sometimes not.

But definitely I always use 2x +2 on default (below qpi and below 4000).

Works good on ram speed.

Regards,
Victor

[C3D76]

Re: 920 Uncore more than dram x 2+2 ?

I tried these everest mem benchmarks some time back:

@ 4.095 Ghz (195x20/21) - Mem 2:8 1560Mhz, 7-7-7-24-74-2t<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
<o:p></o:p>
Uncore x16(3120): 16xxx/13xxx/19xxx 46.7ns...<o:p></o:p>
Uncore x17(3315): 17xxx.14xxx/21xxx 46.3-46.5ns (vtt 1.30v)<o:p></o:p>
Uncore x18(3510): 18218/15444/22647 45.8-46.0ns (vtt 1.32v)<o:p></o:p>
http://img4.imageshack.us/img4/1453/c3d.jpg<o:p></o:p>
Uncore x19(3705): 18686/16281/24060 45.4ns (vtt 1.36v)<o:p></o:p>
http://img15.imageshack.us/img15/2726/uncorex19.jpg

So not worth it beyond x18 (at these clocks with my setup) because of extra voltage and heat as far as I am concerned...

[Lsdmeasap]

Re: 920 Uncore more than dram x 2+2 ?

You can use any you like, to an extent. Some CPU's do not like the uncore to be an odd value, others it does not matter.

When using more than ram multi, you need to increase the Vdimm more and more the higher you go. I have used 4x ram multi before without issues, and I have seen 6x I believe used by Eva2000

[pubem]

Re: 920 Uncore more than dram x 2+2 ?

Thanks guys for the reply ! I will left it on +2 max.

[Lsdmeasap]

Re: 920 Uncore more than dram x 2+2 ?

You can use more if you like, depending on the overall speeds, you just may need more voltages than what would be ideal.

[pubem]

Re: 920 Uncore more than dram x 2+2 ?

Becuase of 12 gb ram I use 1.46 QPI. It is need for default 16x too. (my mem is on 8x). So don't want to push more voltage on qpi..

Thanks !
P

[Lsdmeasap]

Re: 920 Uncore more than dram x 2+2 ?

Ahh ok! Ya with 12GB it may be a bit tougher to use higher uncore