Is the i7 975 just an overclocked 920?

[RealMarkP]

I've always wondered if Intel just overclocks the stock voltage on their CPUs to sell them at a higher price. So, is the i7 975 an overclocked 920? Could I just buy a 920, bump up the voltage to the 975 rates and use it like a 975?

 

[hunter315]

there is a difference, the 975 has a higher multiplier than the 920 so its base clock runs at the same speed, this increases stability a bit. The voltage on all of them is actually the same, its the multiplier that is different which affects the overall clock speed, but if you increase the base clock on the 920 so that you get the same CPU speed as the 975 you will get the same performance for far far less.

 

[marcellis22]

i7-975 http://ark.intel.com/Product.aspx?id=37153

i7-920 http://ark.intel.com/Product.aspx?id=37147

You could try...

 

[RealMarkP]

So what you're saying is that if I mimic the CPU settings of a 975 on a 920, I will get the same performance. Now, that's just raw power, what about the 'Intel® QPI Speed', will it scale as well?

 

[B-Unit]

Well, yes and no.

While the CPU dies of the two processors are identical, each of them went thru a process known as 'binning' where each was tested to determine at what frequency/voltage combination it was able to run. The best performing chips are slated to become Xeon server and Extreme Edition chips, and others fall into the lineup according to their abilities. In this way, all chips will basically run at the same voltage, different clock speeds.

When a manufacturer has their process very well tuned, (which Intel tends to do very quickly) a majority of the dies produced will likely perform at or close to optimum, so once the quota of high end (Xeon and EE) chips is filled, these 'good' dies will be incorporated into lower end products, such as the i7 920. When this happens, the lowend parts gain a reputation for being able to overclock VERY well.

While no overclock is guaranteed, I believe that most recent stepping 920s are able to hit 4.2+Ghz with ease, probably more with good cooling.

 

[RealMarkP]

What you're saying is I should probably wait until Intel refines their process to buy an i7 rig. I'm also curious if the FSB is 'overclockable' on the 920 to match that of the 975.

 

[B-Unit]

As I said, Intel does this very quickly. 920s already OC almost as well as 975 chips do, the major difference being that with the unlocked multiplier on a 975 you can generally get a higher overclock before your motherboard becomes a limit.

 

[warmon6]

What you're saying is I should probably wait until Intel refines their process to buy an i7 rig. I'm also curious if the FSB is 'overclockable' on the 920 to match that of the 975.

I dont think intel going to refine the i7 9xx any more as the those cpus are pretty refined. If you are talking about the i7 8xx then you may want to wait. Although All the i7's are great cpus. Even the early C0 stepping i7 overclocked well. Just not as well as the D0 steeping.