Confused by Sandy Bridge overclocking

[Bollwerk]

Nearly everything I've read about overclocking the Sandy Bridge procs (2500k and 2600k) refer to overclocking the "turbo" mode. As I understand it, the turbo mode is only used when the CPU shuts down cores not in use and cranks up the speed of a single core. Please correct me if I'm wrong here.

It seems that based on this, overclocking a Sandy Bridge wouldn't be useful to us boxers, since we use all available cores.
I hope I'm wrong here.

Also, it seems that some folks have reported hyperthreading seems to sometimes provide slower performance when used for WoW, so would that mean it's better to get the 2500K (only has 4 real cores) than the 2600K (has 4 real + 4 virtual cores)?

One last question - Is it worth the cash (for multiboxing only) to buy RAM that can handle higher frequencies, then run it at those higher frequencies?
i.e. How much would multiboxing performance improve with RAM running at 2000MHz vs 1333MHz for example. Note that CAS timings usually need to be relaxed to achieve higher speeds.

[Kromtor]

sounds like you're right if that's how it works, probably wont help those actually making use of all the cores. it's my understanding that hyperthreading may have been useful back when you were running more processes than you had cores for, but now that that is rarely the case you're seeing it actually be a performance loss.

i doubt anyone could say about the ram without testing it

[Ughmahedhurtz]

http://www.techreaction.net/2011/01/04/3-step-overclocking-guide-%E2%80%93-sandy-bridge-v0-1beta/

I'm guessing the sites you've read are talking about the "free" overclocking or some such. When I read the word "overclocking," it has always meant bumping clock multipliers, v-core and/or memory timings.

[burningforce]

not sure about the memory question

as for overclocking sandy bridge, all you need is either a "i7-2500k or i7-2600k" processor anda decent heat-sink fan. I do not have sandy but from what I read all you do is bump the "multiplier" up in the bios in increments of +5, then you load windows and test with overclocking tools. if it is stable and you want more speed, then you can return to the bios and up the "cpu multiplier" so more. Just keep in mind that whenever you raise the cpu and/or memory speed, you may have to up the cpu and/ore memory voltages.

safe voltages for the cpu would be a maximum of "1.35v" in my opinion (although the intel whitesheet says 1.5v) for 24/7 usage. I have seen forum posts where people have cpu voltage at 1.35v and got a nice 4.0Ghz overclock!!(though your mileage will vary).

here is a guide that is a work in progress
http://www.overclock.net/intel-cpus/908782-sneak-peak-my-sandy-bridge-overclocking.html

as for turbo, that is just an ability of the cpu to raise its speed to match the stress being put on the system by a game or other. I would not even worry about turbo and would advice turning it off if overclocking the cpu.

[Sam DeathWalker]

iirc turbo lets you run faster while the processor is cold, after it heats up it drops back to normal. So like when you first turn the computer on you get some faster speed. Seems like a joke. Not sure though just from memory. Or if the processor it being used a low rates it will be colder so again it can run faster. Of course running it faster makes it heat up ...... lol.

You won't see any use from faster ram imho. Once your data is actually in ram you are A-OK, its getting it into the system ram that is so slow.

Takes what 10 plus times more time to move from HHD or SSD to system ram then from system ram to video ram.

Only reason to get fast ram is to underclock it so that its more reliable. One ram error and you get blue screens that take forever to figure out whats wrong.

It is NOT worth the extra money that you can spend on a SSD or More Ram.

[Sajuuk]

iirc turbo lets you run faster while the processor is cold, after it heats up it drops back to normal. So like when you first turn the computer on you get some faster speed. Seems like a joke. Not sure though just from memory. Or if the processor it being used a low rates it will be colder so again it can run faster. Of course running it faster makes it heat up ...... lol.

You won't see any use from faster ram imho. Once your data is actually in ram you are A-OK, its getting it into the system ram that is so slow.

Takes what 10 plus times more time to move from HHD or SSD to system ram then from system ram to video ram.

Only reason to get fast ram is to underclock it so that its more reliable. One ram error and you get blue screens that take forever to figure out whats wrong.

It is NOT worth the extra money that you can spend on a SSD or More Ram.

Oh...my...god...

You're not remembering correctly. Turbo will throttle other cores of your CPU to give more speed to a some of your other cores to boost performance in an application.

EXAMPLE

Using a cpu intensive program that only uses 2 cores, I have a 4 core CPU, no hyperthreading.
Using cores 1,2. Cores 3,4 get throttled to boost performance in cores 1,2.

THAT IS TURBO MODE. Has nothing to do with "Temperature". Running faster does not mean you run slower, it just means you need to cool your processor better to get more speed out of it.

As far as RAM goes, only buy high speed ram if you actually plan on using it through overclocking.


One ram error and you get blue screens that take forever to figure out whats wrong.

What? What?

A couple things: STOP error codes, which can be looked up in your event viewer.



And sandy bridge overclocking is with the multiplier only.

[burningforce]

also my original post was incorrect, you can only overclock the turbo mode. so turning that off (if you can) will not allow you to O'C it.

here is a video that explains it a little bit + review
http://www.youtube.com/watch?v=PSET4P6EZ30

also blue screens with sandy bridge means not enough voltage for the cpu. upping the cpu voltage a little
can go a long way. A safe limit to the max voltage is 1.35v

[Sajuuk]

also my original post was incorrect, you can only overclock the turbo mode. so turning that off (if you can) will not allow you to O'C it.

here is a video that explains it a little bit + review
http://www.youtube.com/watch?v=PSET4P6EZ30

also blue screens with sandy bridge means not enough voltage for the cpu. upping the cpu voltage a little
can go a long way. A safe limit to the max voltage is 1.35v

Overclock the turbo, overclock, either way you're still getting more speed.

[Sam DeathWalker]

http://www.pugetsystems.com/blog/2009/02/26/intel-core-i7-temperatures/

I7's throttle down at temps over 100 C. Thats what I was thinking of.

What we’ve found is that the Intel Core i7 CPUs throttle down their speed starting at 100C. So, 100C is the maximum operating temperature of Intel Core i7. However, due to the great power management, we have never seen instability due to temperature



Ram errors are "random" because a spicific address in ram may one time hold one kind of data and next time you power up a different kind of data which might give different error codes which makes ram errors hard to pinpoint. Plus if its a ram error the blue screen code has NOTHING to do with the error, because the ram returns wrong infromation (we don't use ECC ram), which could be random depending on how the ram fails. So while you are looking up the errror code you are wasting time casue that not the problem at all. For example you get a blue screen error code and then you replace the ram and everything is fine. Did the error code tell you that the ram was bad? Doubt it.


Here is infos on overclocking Sandy Bridge:

http://news.softpedia.com/news/Intel-Sandy-Bridge-Overclocking-Potential-Explored-177765.shtml



Anyway I would not overclock a cpu as if you want a faster cpu just buy a faster cpu. CPU is not boxers problem, our problem is getting data from the SSD or the Hard Drive (textures) into system ram.

Spend your money to fix that up (i.e. faster SSD).

Spend your money here first (well get a X58 system though) then worry about your ram speed or cpu speed: And get as much ram on the video card as you can.

http://www.ocztechnology.com/products/solid-state-drives/pci-express/z-drive-r2.html

Well those are a bit costly lol.... I use a revo but those are better ...