Memory overclocking is completely independent of CPU overclocking on Sandy Bridge systems. Also, overclocking the RAM isn't necessary as Sandy Bridge's memory controller is quite good. Besides, unless you got very good quality 1600 memory, it is unlikely to overclock to the next step up (which is 1866).
For a 4.5GHz overclock:
1. Change CPU multiplier to 45 in BIOS
2. Save and exit
Run Prime95 Blend test. Using programs like CPU-Z and Core Temp or CPUID Hardware Monitor, monitor the CPU voltage and temps while the CPU is loaded. The CPU voltage should be 1.3-1.35v. If it's within that range, great. If it's not, then you will need to adjust the CPU voltage in the BIOS.
To keep Sandy Bridge happy for a long-term overclock:
1. Keep peak Prime95 core temps below 75ºC
2. Keep CPU voltage below 1.4v
so just adjusting the multiplier will change the speed right..my stock voltage is 1.3 ..can i enable the turbo boost and increase the multiplier..
my friend want to buy a cpu he is asking me a question.my rig is i7 2600k ..asrock p67 pro 3 and gtx 570..but i have aan other specs to suggest him that is ..he can buy a same asrock p67 pro3 mobo ..get an i5 2500k processor as he save some money i prefer to invest him in the graphic card like a gtx 580..will an i5 2500k processor can withstand gtx 580
FYI, there's usually only two reasons to overclock a modern CPU like yours:
1) Transcoding video with a program that uses all threads (in which case I recommend putting the settings back to default after you are done)
2) SLI or Crossfire of high-end Graphics cards (i.e. 2xHD5870, 2xGTX560Ti or higher. *Varies significantly between games. Some won't benefit from a CPU overclock even with 2xHD5870)
If you fall into the video game category, there's a simple way to test (each game) to see where you stand:
1) Open Task Manager (CTRL-ALT-DEL)
2) look at "performance"
3) settings to "View->Update Speed->LOW" and "View->CPU History->One graph per CPU"
4) In general, ignore the Hyperthreads if enabled. For a quad-core, if enabled you'll see 8 graphs. Ignore the 2nd, 4th, 6th, and 8th (Core's start at "0" so that's Core#1,3,5,7)
5)Run a game for at least five minutes of gameplay, close the game, leave TM still running and observe the results:
Analysis of Task Manager and CPU results during gameplay:
*This was much simpler when:
a) there was one core, and
b) there was no hyperthreading.
Basically, when there was a single-core CPU, if the CPU was peaking at 50%, this meant that your system could handle a graphics card that was 2x faster or TWO CARDS (SLI or Crossfire).
It's different now with multithreading because games can rarely use all cores (and many don't ever touch the threads. Again, ignore those.
General analysis of results:
Scenario #1: NONE of the cores (0,2,4,6) ever reach 100%
Analysis: The CPU would provide NO benefit to the game by being overclocked
Scenario #2: Only ONE core reaches 100% out of four physical cores.
Analysis: It is likely that overclocking would provide much benefit, possibly none. If the game has a good benchmarking tool built in, you can try overclocking the CPU (change no other settings) and see if this changes the benchmark results.
Scenario #3: Two or more cores reach 100%.
Analysis: It's quite certain overclocking the CPU would improve performance.
Exceptions to the above:
If you have the game CAPPED by using VSync and it NEVER falls below the capped rate (usually 60FPS) then overclocking the CPU would not benefit anything because the game will not increase the frame rate and therefore needs no additional processing from either the CPU or Graphics card.
1. Overclocking a modern CPU is usually only needed for transcoding video, similar tasks, or for playing video game on a system with two or more high-end graphics cards.
2. It is possible using the Task Manager to determine if overclocking your CPU would benefit a particular game.
3. CPU usage in games may vary between 20% and 60% on the same setup (i.e. an HD5870 or GTX560Ti).
4. Ignore hyperthreads for most analysis when observing the CPU performance graphs
5. NEVER use the average CPU usage as an indication of how stressed your CPU is. (You could actually use 100% of all physical cores, but still show only 50% CPU usage even though the game can't even use the Hyperthreads. Not only is it incorrect that you have 50% "left" of your CPU, the Hyperthreads, at best can only add 30% additional processing power but they are averaged as EQUAL to a CPU physical core.
6. Generic BENCHMARK UTILITIES should not be used in this scenario because they ADD UP the graphics and CPU results. Overclocking a CPU would create a higher score in this case. however, the whole issue is that the graphics card can be the bottleneck, so in a game scenario overclocking the CPU may NOT have any positive effect.
7. ****MOST IMPORTANTLY:
If you need to overclock your CPU due to a specific game, or games, only overclock it enough so that no additional overclocking would benefit the game. Overclocking adds heat, fan noise, and wears out the CPU prematurely.
It's often difficult for memory to be the bottleneck. Basically, the memory sends information to the CPU to be processed so the faster the CPU runs, the faster the memory needs to be.
However, let us consider that in a VIDEO GAME, a modern CPU like the i7-860 paired with an HD5870 averages no more than 20% of it's available processing power (including threads).
We need to include the hyperthreads in this scenario. Let me explain:
I have 1600MHz RAM (amount does not matter), an i7-860 (just slightly less than what you have). The video card does not matter in this scenario.
If I run a program like Handbrake, I am able to transcode (convert) video using 100% of my CPU processing power, including hyperthreads AND overclocked to 3.8GHz.
*The fact that I'm hitting 100% on every core means my RAM (System Memory) running at 1600MHz is fast enough to supply the CPU. In otherwords, there's NO NEED TO OVERCLOCK THE RAM.
If my RAM is fast enough to supply all 8 threads, overclocked to 3.8GHz, it's certainly fast enough for games, that even using multiple cards can't use 100% of my CPU.
It's very difficult to find situations in which more than 1600MHz would be insufficient for a quad-core/8-thread system, even if overclocked to 4.5GHz. I suspect that you would need an overclocked 12-thread CPU for this to even be a possibility.