QPI frequency?

[David J]

In my BIOS I did some experimenting with the QPI frequency in that I moved it from 4.6 (lowest) to 6.4 (highest). The BIOS as well as the system accepted the change, but in doing so I now get the dreaded double boot. I tried the change in order to see some speed improvement in overall speed, but I didn't. Does anyone know why increasing the QPI frequency would not translate to faster overall speed? As a general rule I thought that the higher the frequency the faster it is for moving the 1s and 0s around. That general rule does not seem to apply to OPI frequency? Since there was not a noticeable improvement in speed as well as to get rid of the double boot I changed the BIOS setting back to 4.6. I can't prove it with numbers (yet), but the system seems faster on the lower 4.6 setting?

 

[Jack the Newbie]

Hi,

I just found this article which includes a few benchmarks that show the impact of QPI Frequency:

http://techgage.com/article/intel_core_i7_performance_preview/12

As it looks, there is no significant benefit at all.  That article may not answer your question, but at least it shows that your test results are not that unusual.

 

[Aaron]

In extension to Jack's post:

QPI is fast enough at 4.8 GT/s.  I'm assuming the 6.4 GT/s exists for server based operations where more bandwidth is required.  As servers have to not just connect and communicate with the system itself, but with other processors (not always, though).

HyperThreading will give you the biggest performance boost, excluding overclocking.  So ensure you have it enabled.

 

[David J]

Thanks! I forgot that I started this thread, but since then I have done a lot of reading on the QPI including the article linked above. I've come to the conclusion that for today's software the lowest setting is way more than fast enough. One can liken the QPI to a 4.6 inch diameter pipe that for the here and now never passes more than 1 inch of water. Having a 6.4 inch diameter pipe only makes it that much more ridiculous. However, down the road should software change to the point that I ever need to pass greater than 4.6 inches of water through my 4.6 inch pipe it's nice knowing I have a 6.4 inch pipe standing by in the BIOS.
  I digitize video quite often on my new MSI I7 based PC and I can tell you HT is simply amazing. The digitizing that used to take an hour on my old P4 now takes 7 minutes on my new I7 with HT. This includes MPEG2, MPEG4 and HD. With the P4 I literally used to set up the PC to encode over night after I went to bed. With the I7 and HT I have yet to spend more than an hour encoding. Amazing!

 

[Tommichiels]

If you o.c your cpu with qpi clock at 4.8GT/s you will see that your qpi clock will go up while you overclock.
For example my qpi is set in bios at 4.8GT/s but with my overclock it is 6.4GT/s.
Check this with the intel processor ID utility or with cpu-z.

 

[David J]

If you o.c your cpu with qpi clock at 4.8GT/s you will see that your qpi clock will go up while you overclock.
For example my qpi is set in bios at 4.8GT/s but with my overclock it is 6.4GT/s.
Check this with the intel processor ID utility or with cpu-z.

You lost me on that one? I'm overclocking my base clock with the OC switch on the mobo, but my QPI remains 4.6 in the BIOS. On the CPU-Z I have I do not see a reading for anything other than QPI link (2407 MHz). How does that equate to 4.6 GT/s, or 6.4 GT/s?

 

[HU16E]

Since the i7 920 & the 940 only natively support 4.8 GT/s, that could explain why they want to 'double boot' in the boards that have the setting at 6.4.

 

[David J]

You got it! I can change my QPI frequency to 6.4 and it'll still run all day long, but when I turn it on I get the dreaded double boot. When I change it back to 4.6 all is normal with the boot. I've read that overclocking the base clock automatically changes the QPI frequency, but if that is so it never shows in my BIOS read outs. I've changed my base clock all the way to 180 and the QPI frequency in the BIOS showed 4.6 the entire time. Since I saw no improvement in any of the overclocking past 166 on the base clock I left it there. This nets me 3.32 GHz with the CPU and 1333 MHz with the memory. Oh BTW I left the memory setting on AUTO when I was changing the base clock in the BIOS. The memory will run as high as 1700, but I didn't see the point in stressing the components for no perceptible improvement.

 

[joker1973]

I think Tom wants you to get this utility---http://downloadcenter.intel.com/confirm.aspx?httpDown=http://downloadmirror.intel.com/7838/eng/pidenu21.msi&agr=N&ProductID=1881&DwnldId=7838&strOSs=All&OSFullName=All%20Operating%20Systems&lang=eng. It shows useful info about expected and reported speeds.  At 4.0 GHz my QPI is at 6.85GT/s yet in the bios I have it set to 4.8.  So if you overclock a 920 to 3.2 GHz (I7 965) your QPI will run at 6.4GT/s.  Increase BCLK and the QPI will go up as well.  I only get the double boot after I change the BCLK or major voltage settings, and only one time after the change.

 

[David J]

Thanks for the tip as well as utility. According to the utility and as you stated my QPI frequency was automatically raised with the base clock even though my BIOS reported something different.

 

[joker1973]

No problem.  I also came from a P4 and these new systems are off the hook.  6 min encoding vs. 2 hour snail race.  I can't stop playing with this thing! :grin:

 

[David J]

I came from a P4 also. I love the fact that I paid $700 less than the premium processor, but yet I have equal to greater processing power! Can't beat it!

 

[Aaron]

I came from a P4 also. I love the fact that I paid $700 less than the premium processor, but yet I have equal to greater processing power! Can't beat it!

That logic is flawed.  You can just as easily overclock a flagship processor way beyond the others.

 

[David J]

True, but overclocking is still an enthusiast's game. 9/10 of the people that bought the premium processor will not overclock, or even know what that is. I bought the I7 920 with a mission to spend way less money than those that bought the premium processor, but yet out power them. That sir is perfect logic as well as achieved!

 

[Aaron]

If you're shelling out ?800 on a CPU, I'm rather confident you know how to use it.  I've never met anyone that's bought an XE CPU and never known its potential.

 

[David J]

Then you need to step outside your circle WAY more often. I'm a degreed Engineer working in a computer manufacturing environment. 9 out of 10 people I talk to have no idea what overclocking is. Nor do they have any idea that you can build your own PC. Most people go to Best Buy and Radio Shack to buy a computer. People that consider themselves knowledgeable go on-line to Dell, or Gateway. Face it people that know about overclocking and building their own PC are less than 1% of the computer buying world! We're way off topic here, but I couldn't resist that one!

 

[Aaron]

Then you need to step outside your circle WAY more often. I'm a degreed Engineer working in a computer manufacturing environment. 9 out of 10 people I talk to have no idea what overclocking is. Nor do they have any idea that you can build your own PC. Most people go to Best Buy and Radio Shack to buy a computer. People that consider themselves knowledgeable go on-line to Dell, or Gateway. Face it people that know about overclocking and building their own PC are less than 1% of the computer buying world! We're way off topic here, but I couldn't resist that one!

Yes, the majority of computer buyers do not know what overclocking is, most could not even fathom building one.  That still doesn't change the fact I've never known someone to buy an XE CPU and not know what to truly do with it.  Have you?  If so, then I can understand the reasons for your opinion.

Compared to someone who has purchased an XE CPU with the intent of overclocking it, your logic is most certainly flawed.

 

[HU16E]

It will be interesting to see how David J's 920 stacks up to the shiny new D0 stepped 975 whenever they release it. :lol_anim:

 

[joker1973]

I want one.   Will wash dishes and cut grass for 975, especially if it's shiny!! 

 

[David J]

Yes, the majority of computer buyers do not know what overclocking is, most could not even fathom building one.  That still doesn't change the fact I've never known someone to buy an XE CPU and not know what to truly do with it.  Have you?  If so, then I can understand the reasons for your opinion.

Compared to someone who has purchased an XE CPU with the intent of overclocking it, your logic is most certainly flawed.

What's flawed is what you say. You recognize that most computer buyers don't know what overclocking is much less how to build one, but then you ask me if I've known someone that has bought an XE and doesn't know what to do with it. Contradiction and YES anyone who has ever bought a computer from Dell! Have you ever seen a BIOS from a Dell? In case not I'll tell you they are stripped down to nothing! Regardless I'll answer your question for a 2nd time! 9/10 of the people that will buy an XE will leave it stock and never open the case! An exact case and point is the guy that runs IT where I work. He has a Master's degree in computer engineering. He builds by hand most of the work stations for the company. He has heard of overclocking, but has never tried it even with his personal PCs. He fears warranty violation and doesn't believe there is that much to gain against what could fail. I'd say he represents 95% of computer professionals. I'll say again what we talk about here is a minute section of the market called enthusiasts. We are less than 1% of the entire computer market. Not counting game consoles. The game console world has a much higher percentage of enthusiasts.