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INTEL Sandy Bridge - NO FSB OC?!?!

O

OC-Chronic

Limp Gawd
Joined
Sep 14, 2010
Messages
234
Did I hear correctly that the clockgen is on-die, on S1155 procs, so FSB overclocking is in practical terms, impossible?!?! That really sucks because you need an unlocked CPU to overclock now, if true. I've really gained alot of bandwidth & lowered latencies by OC'ing the crap out of my E8600, via the FSB & a lower Multi.

If so, I might be shifting over to the green side after playing wiht my DFI X58 boards...:(
 
OC-Chronic said:
Did I hear correctly that the clockgen is on-die, on S1155 procs, so FSB overclocking is in practical terms, impossible?!?! That really sucks because you need an unlocked CPU to overclock now, if true. I've really gained alot of bandwidth & lowered latencies by OC'ing the crap out of my E8600, via the FSB & a lower Multi.

If so, I might be shifting over to the green side after playing wiht my DFI X58 boards...:(
Click to expand...

Mmm where's your memory controller again?
 
Yep you have to get an unlocked one and mess with the multiplier, which kind of sucks in another way (besides the price premium) which is that you have to jump in big steps, you might be "almost" stable at one multiplier and might have been able to knock it down a couple of baseclock mhz, but no, you have to loose an entire multiplier.

I somehow doubt there are ever going to be any unlocked versions of the 8+ core xeons either, so a beast like the SR-2 will not have any reason to exist.
 
You can easily get any increment between multipliers by tweaking the BCLK slightly. But yes the primary OC method on Sandy Bridge is multipliers, which are only unlocked on the -K processors and multipliers can only be raised on the P67 boards, not H67.
 
If "fsb" overclocking is more important to you then actual performance, by all means you should move to AMD. Rest assured those with Intel K series will get better performance regardless how much theoretical bandwidth you may have coaxed out of your AMD machine.
 
Given that you can see 4.8GHz pretty easily out of Sandy Bridge parts on most P67 Express chipset based boards (if not all of them) with fairly modest cooling I wouldn't worry too much about overclocking via the bus clock. Which BTW, your X58 doesn't use an FSB either. It uses a bus clock. The only difference is that Sandy Bridge has the clock generator on die now. Yeah bus clock overclocking is more or less dead but as long as they have the K-Series parts it doesn't matter. They aren't that expensive either. The 2500K is only $199.99 and the 2600K is only $299.99.

And latencies didn't mean all that much on the Core 2's anyway. Increasing the bus clock doesn't net you lower latencies, adjusting your memory timings do. There is a certain amount of potential theoretical bandwidth achieved by overclocking the bus clock and the memory bus, the latter of which can still be done on Sandy Bridge parts almost freely. Intel's processors have always been a different beast than the socket 754 and 939 AMD processors that thrived on low latencies and Hypertransport tweaks. With Core 2's it didn't matter much because the memory controller wasn't on the die. Hell Intel's Core i7's don't really benefit that much from latency timing adjustments either. They certainly don't show any real world gains when tweaking their QPI settings. Intel processors just don't need tweaks like that. There is nothing wrong with doing it, but if the trade off of going with Sandy Bridge is a $200 processor that can reach 4.7GHz or better with all the processor features including power management enabled then I'd say good riddance to bus clock adjustments. Sure it may have been more fun for some people to overclock LGA1366 and AM3 processor based setups but at the end of the day I'm more impressed with results. I can get a Sandy Bridge processor to it's highest speeds and validate the overclock in far less time than I can with anything else.
 
OC-Chronic said:
Did I hear correctly that the clockgen is on-die, on S1155 procs, so FSB overclocking is in practical terms, impossible?!?! That really sucks because you need an unlocked CPU to overclock now, if true. I've really gained alot of bandwidth & lowered latencies by OC'ing the crap out of my E8600, via the FSB & a lower Multi.

If so, I might be shifting over to the green side after playing wiht my DFI X58 boards...:(
Click to expand...

Yeah. It's been well documented for months before launch. Intel hasn't even had a FSB in quite some time (1366 had QPI, 1156 had DMI).

There was a big fuss about it last summer, and everyone made the same remarks you just did, including empty threats to move to AMD. It was an issue at the time, because the "K" unlocked processors on Nehalem were much more expensive than their regular counterparts. IIRC, they had a i5-655K, i7-875K, and a couple "Extreme Edition" i7-9xx that were a significant price premium. So everyone starts freaking out because they expect the regular i5 to be $200, regular i7 to be $300, and the "K" versions to be $100 more.

but, they come out, and it turns out the price difference isn't $100, it's like $15-20. And the chips can hit a huge overclock really easily, even on air. And you don't need more expensive RAM to get stability.
 
nalc said:
but, they come out, and it turns out the price difference isn't $100, it's like $15-20. And the chips can hit a huge overclock really easily, even on air. And you don't need more expensive RAM to get stability.
Click to expand...

Not only that but you get to choose your RAM and CPU speed without regard for one another. You buy RAM that'll work at the speed you are willing to pay for, and it just works at that speed. You OC your CPU to the level it is stable at (or the level you are happy with) without worrying about the RAM.

It isn't like ye olden days when you had to buy RAM that could deal with increased bus speeds.

There doesn't really seem to be a lot of downside except that Intel wants a little more money for their OC parts. However as you said, it is like $20 so no big deal.

Given that they OC like beasts and there is no fiddling about to do it, I can see little room to complain.
 
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The sky is so totally falling.

You can...

-Easily adjust multiplier to see large gains quickly.
-Tune BCLK (generally 1-3MHz, sometimes as high as 5) to tweak in between that if for some reason you want 4.75GHz instead of 4.7GHz or 4.8GHz.
-Do this, in all likelihood, in software, safely, on any number of motherboards.
-Never have to worry about stupid things like RAM dividers.
-Buy a chip that could potentially hit anywhere between 4.5GHz and 5.0GHz stably overclocked on air for under $200.
-Do all of this with C1 and EIST turned on, so there's even a slight savings in operating costs when you're idling or otherwise not loading the CPU heavily.

What the crap, Intel?!

No, really though, just consider the K parts the actual prices of Intel's chips, and look at the non-K parts as discounted SKUs for people who don't want to overclock. The 2500K is regularly available for under $200, and the 2600K for under $300. Either will, in many benchmarks, either give a 980X Gulftown a run for its money or just go and curbstomp it (usually the latter, in the real world). Good value for money there. And even non-overclocked non-K parts will do the same thing, only more running, less stomping.
 
To me this limitation and the feature segmentation of the different chipsets and especially locking out vt-d from K series processors has annoyed me a bit however without real competition from AMD Intel will do what it wants.
 
Core i3 & i5 2100 series = fully locked
CPUs are fully locked, the multiplier cannot be increase beyond the factory setting.
Core i5 & i70„2 non-K series = partially unlocked
CPUs are partially unlocked, the multiplier can be adjusted up to 4 the factory setting.
Core i5 2500K & i7 2600K = fully unlocked
CPUs multipliers can be freely adjusted up to x57

CPU frequency = bclock x CPU clock ratio
Memory frequency = bclock x System Memory Multiplier (SPD)

Intel has buried the clock generator inside the cpu but everything still evolves around the Bclock. You just use the ratio by working of the 100mhz Bclock.
 
Dan_D said:
Given that you can see 4.8GHz pretty easily out of Sandy Bridge parts on most P67 Express chipset based boards (if not all of them) with fairly modest cooling I wouldn't worry too much about overclocking via the bus clock. Which BTW, your X58 doesn't use an FSB either. It uses a bus clock. The only difference is that Sandy Bridge has the clock generator on die now. Yeah bus clock overclocking is more or less dead but as long as they have the K-Series parts it doesn't matter. They aren't that expensive either. The 2500K is only $199.99 and the 2600K is only $299.99.

And latencies didn't mean all that much on the Core 2's anyway. Increasing the bus clock doesn't net you lower latencies, adjusting your memory timings do. There is a certain amount of potential theoretical bandwidth achieved by overclocking the bus clock and the memory bus, the latter of which can still be done on Sandy Bridge parts almost freely. Intel's processors have always been a different beast than the socket 754 and 939 AMD processors that thrived on low latencies and Hypertransport tweaks. With Core 2's it didn't matter much because the memory controller wasn't on the die. Hell Intel's Core i7's don't really benefit that much from latency timing adjustments either. They certainly don't show any real world gains when tweaking their QPI settings. Intel processors just don't need tweaks like that. There is nothing wrong with doing it, but if the trade off of going with Sandy Bridge is a $200 processor that can reach 4.7GHz or better with all the processor features including power management enabled then I'd say good riddance to bus clock adjustments. Sure it may have been more fun for some people to overclock LGA1366 and AM3 processor based setups but at the end of the day I'm more impressed with results. I can get a Sandy Bridge processor to it's highest speeds and validate the overclock in far less time than I can with anything else.
Click to expand...

Because it has bigger caches which hide most of the rams latency
 
Spooony said:
Because it has bigger caches which hide most of the rams latency
Click to expand...

I don't think that's the only reason. The gimpy cache models (Celery's etc.) didn't really show any real improvement from such tweaks either.
 
Yep you have to get an unlocked one and mess with the multiplier, which kind of sucks in another way (besides the price premium) which is that you have to jump in big steps, you might be "almost" stable at one multiplier and might have been able to knock it down a couple of baseclock mhz, but no, you have to loose an entire multiplier.
Click to expand...

Except if you knock it down one multiplier, you can go mess with the BCLK/PEG frequency to fine tweak in-between the 100MHz multi increments.

And some of you act like "paying more" is such a big deal? Hello!! Q6600s were over $300 (over $500 for a while when they were released) and with those all you could hope for was higher than 3.2GHz. Same with the Q9xxx except those clocked higher.
 
blade52x said:
Except if you knock it down one multiplier, you can go mess with the BCLK/PEG frequency to fine tweak in-between the 100MHz multi increments.

And some of you act like "paying more" is such a big deal? Hello!! Q6600s were over $300 (over $500 for a while when they were released) and with those all you could hope for was higher than 3.2GHz. Same with the Q9xxx except those clocked higher.
Click to expand...

Actually the Q6600 was originally $850 and then dropped to $500 before dropping even further. Really though getting more than 103MHz out of the bus clock is a bit tough to do. Granted we are talking about fairly high multipliers with these chips.
 
Didn't we cover this a month or two ago?

At best we're realistically looking at 5-7MhZ on the BCLK. This is partially to do with the fact that the controller is on the CPU and PCIE is finicky about overclocks beyond that. You may be able to bump it up to 10 or 15 but instability will likely run rampant.

Unlocked multiplier is really all you need, the majority of SB chips are 4.6-4.8GhZ capable on air, ~10% are figured to be 5GhZ capable on air.
 
Sycraft said:
There doesn't really seem to be a lot of downside except that Intel wants a little more money for their OC parts. However as you said, it is like $20 so no big deal.
Click to expand...
However only the top two LGA1155 chips have unlocked versions. So the days of buying a cheap Intel CPU and overclocking it are over.
 
plugwash said:
However only the top two LGA1155 chips have unlocked versions. So the days of buying a cheap Intel CPU and overclocking it are over.
Click to expand...

Given that the Core i5 2500K is only $199.99 at Microcenter, I don't think so. People paid well more than that for Q6600's and even the E6400, E8400 were fairly close to the price of the 2500K in their respective reign as highly desirable enthusiast parts. I think somewhere between $160 and $220 for a processor is reasonable for most enthusiasts. That's about what they've been paying for several years now, and in some cases quite a bit more.
 
The K variants are barely more expensive than the regular and offer by far the best value ever to come out of Intel especially now that the chipset problem is behind us and motherboard (including budget boards) are now more widely available. The fact that Intel is embracing overlocking AT ALL now is a huge step forward. They openly advertise the overclocking potential of these chips.

Complaining about VT-d on a platform that nobody claims is for the enterprise sector is a bit dumb imo. Are you going to argue that your Ferrari can't pull your boat?
 
bigddybn said:
The K variants are barely more expensive than the regular and offer by far the best value ever to come out of Intel especially now that the chipset problem is behind us and motherboard (including budget boards) are now more widely available. The fact that Intel is embracing overlocking AT ALL now is a huge step forward. They openly advertise the overclocking potential of these chips.

Complaining about VT-d on a platform that nobody claims is for the enterprise sector is a bit dumb imo. Are you going to argue that your Ferrari can't pull your boat?
Click to expand...

That's a fair point. The overclocking enthusiast isn't generally the same guy who cares about VT-d and even if they are, chances are they've got more than one machine at their disposal. My concerns for my servers, HTPC etc. differ from that of my gaming machine for example.
 
I complain about that (vt-d) because on my home 64 bit linux desktops I need to run 64 bit clients from other operating systems and I need to do this without the normal disk penalty of virtulization on top of that I do a little overclocking..
 
drescherjm said:
I complain about that (vt-d) because on my home 64 bit linux desktops I need to run 64 bit clients from other operating systems and I need to do this without the normal disk penalty of virtulization on top of that I do a little overclocking..
Click to expand...

Then it doesn't sound like the Core i5 2500K is for you. A stock Core i5 2500K for example generally runs at 3.7GHz with it's turbo mode enabled which isn't bad at all.
 
Omophorus said:
No, really though, just consider the K parts the actual prices of Intel's chips, and look at the non-K parts as discounted SKUs for people who don't want to overclock. The 2500K is regularly available for under $200, and the 2600K for under $300. Either will, in many benchmarks, either give a 980X Gulftown a run for its money or just go and curbstomp it (usually the latter, in the real world). Good value for money there. And even non-overclocked non-K parts will do the same thing, only more running, less stomping.
Click to expand...


I would love to see where the 2500K is regularly available for under $200 to people who don't live next to a Microcenter or Fry's :p

*just bought a Core i5 2400*
 
ocellaris said:
I would love to see where the 2500K is regularly available for under $200 to people who don't live next to a Microcenter or Fry's :p

*just bought a Core i5 2400*
Click to expand...

If you don't, you're living in the wrong parts of the country. :p
 
Ok...thanx all for the input...I did get good gains from OC'ing the FSB on the 775 chipsets like the P45 & X48 & as long as I kept the Perf. level or tRD as low as possible I could get 10000+ read/write/copy out of my DDR2 @ almost 1200-5,5,5,5,18,2T...But that was on a DFI setup which needed alot of manipulation of the GTL's, sub-timings & voltages...so yeah, alot of work & alot of parts had to come together right, to get there....

The next question is:

Will INTEL continue to offer unlocked procs that do 4.5GHz+ once this type of platform is widely adopted, and at such a good price point?? We'll have to wait & see I guess...
 
blade52x said:
Except if you knock it down one multiplier, you can go mess with the BCLK/PEG frequency to fine tweak in-between the 100MHz multi increments.

And some of you act like "paying more" is such a big deal? Hello!! Q6600s were over $300 (over $500 for a while when they were released) and with those all you could hope for was higher than 3.2GHz. Same with the Q9xxx except those clocked higher.
Click to expand...

My Q6600 ran at 3.6ghz for a bit over 3 years before the graphics card smoked the MB and PSU.
 
Just wait for the actual Enthusiast socket to hit the market (Socket 2011). Base Clock overclocking will be present. You have to remember that Socket 1155 is not a replacement for 1366, it's a Mainstream socket and a replacement for 1156. The fact that 1155 is showing such substantial performance over Bloomfield is very promising for their upcoming Enthusiast socket.
 
Just wait for the actual Enthusiast socket to hit the market (Socket 2011). Base Clock overclocking will be present.
Click to expand...

I believe there will be no overclocking at all with socket 2011 however we will have to see.
 
nzaneb said:
Just wait for the actual Enthusiast socket to hit the market (Socket 2011). Base Clock overclocking will be present. You have to remember that Socket 1155 is not a replacement for 1366, it's a Mainstream socket and a replacement for 1156. The fact that 1155 is showing such substantial performance over Bloomfield is very promising for their upcoming Enthusiast socket.
Click to expand...

I've seen nothing that indicated base clock will be adjustable on Socket 2011 (anymore than it is on 1155). Where did you hear that?
 
Forceman said:
I've seen nothing that indicated base clock will be adjustable on Socket 2011 (anymore than it is on 1155). Where did you hear that?
Click to expand...

Internet crystal balls. People just assume because its the enthusiast platform it will have what they want on it :D
 
Omophorus said:
What the crap, Intel?!

No, really though, just consider the K parts the actual prices of Intel's chips, and look at the non-K parts as discounted SKUs for people who don't want to overclock.
Click to expand...
Modest overclocking up to 4 bins (400MHz) is available on non-K processors through turbo speed adjustments.

I know this is an enthusiast board, but believe it or not, overall relatively few CPUs Intel sells will ever be overclocked. The premium for an unlocked processor is relatively cheap for SB models, and makes the entire process much easier than fiddling with various settings and running other hardware out of spec as was done in the past. Really, is the $15-$30 price difference really worth whining about when it simplifies overclocking so much?
 
Forceman said:
I've seen nothing that indicated base clock will be adjustable on Socket 2011 (anymore than it is on 1155). Where did you hear that?
Click to expand...


it will have it.. intel would be stupid not to support it. the reason the 1155 socket has such limited overclocking is due to the on-chip IGP. because overclocking the processor with the FSB(bclk) would cause the IGP to overclock at the same time. the E series(socket 2011) will NOT have an IGP. so there will not and should not be a limitation to overclocking the processor.
 
sirmonkey1985 said:
it will have it.. intel would be stupid not to support it.
Click to expand...

Because they would be worried about AMD? Come on, people are banging out 4.4+ GHz overclocks all day long with 2500K chips, they aren't being held back like you think.
 
sirmonkey1985 said:
it will have it.. intel would be stupid not to support it. the reason the 1155 socket has such limited overclocking is due to the on-chip IGP. because overclocking the processor with the FSB(bclk) would cause the IGP to overclock at the same time. the E series(socket 2011) will NOT have an IGP. so there will not and should not be a limitation to overclocking the processor.
Click to expand...

Limited overclocking? Are you talking about the same CPU?

FSB overclocking is a hackjob to circumvent a CPU multiplier lock. We are just now finally able to do any real overclocking. This I think we can thank AMD for.
 
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