Quote Originally Posted by SF3D View Post
What are you talking mate

QPI is Quick path interconnect speed. It is marked as GT/s Gigatransfers per second. You see this value in CPU-Z front page "QPI link" At stock speed it is saying ~3200MHz, when it should say 6400GT/s(2x3200GT/s). When you raise BCLK this value will raise too and with lowest QPI multiplier (36x) it will go up to ~8000GT/s before it locks. Now if we would have lower multipliers than 36x we could get our BCLK higher before that ~8000GT/s limit.
GT/s is a marketing name and the actual qpi multipliers are 18x 21x and 24x.
18x133=2400Mhz=4800GT/s
21x133=2800Mhz=5600GT/s
24x133=3200Mhz=6400GT/s

gigiabyte calling the multipliers 36 42 and 48 is just confusing and its beyond me why they do this.

Quote Originally Posted by SF3D View Post
If you remember AMD 64 days and 1X to 5X HT multipliers, you will see what this issue is. Back then you had to lower HT multiplier to 4X or 3X to get your HT speed up to 200 to 250.

After all this processor is designed for servers and these really high QPI speeds were not what they had in mind. Maybe this will be fixed with new chipsets or 1160 processors. If QPI multipliers on X58/core i7 are limited to 36x on hardware level, there is nothing we can do. Just LN2 to CPU and Chipset and we might see some scaling

Are we on the same page now
i dont think so, intel is very aware that qpi multipliers are limiting the bclock, and that this limits how high you can overclock their cpus. they know it and they want it, otherwise why would anybody by a 965?

for every clock domain you have a set of registers to program the available multipliers, for the cpu, memory, uncore, and qpi... only qpi has a set of registers that defines a min qpi multiplier, so you can NOT use lower qpi multipliers than 18x. they didnt do this by accident or didnt think about how it limits overclocking...

and regarding slow mode, BloodRage has this as well, and weve been playing a lot with it, but it doesnt work... oh and the slow mode clock is actually not 100mhz, its 67MT/s which is 0.067GT/s wich is 0.033Ghz which is 33Mhz

thats the speed qpi runs at when the processor initializes, but as soon as thats done it forces a qpi multiplier of at least 18...