Which one is better, the Core 2 Duo E7400-7600 or the E8600 for overclocking?
Which one is better, the Core 2 Duo E7400-7600 or the E8600 for overclocking?
I'm really sorry if anyone is annoyed by this post. It's a little bit messy because I am new at overclocking stuff. These questions are probably old and hard to find answers in the forums after three months of searching. So please help me out here. Here is what my computer looks like: Mainboard: P5Q-Pro Memory: 8GB RAM running at 800Mhz Power Supply: Masterwatt Cooler Master 650W Case: Unknown CPU: Core 2 Duo I want to run PCSX2. This software cares more about the core speed than L2 Cache, so I need a super-fast C2D CPU because E7500-7600 have a higher multiplier than E8600. That means they can boost their core speeds higher than E8600. Is this right? 1/ Why does everyone usually prefer the Q6600 or Q6700 over the Q9XXX series? 2/ Someone told me that I shouldn't set FSB higher than DRAM speed. Is it true? My RAM can't be overclocked, so its speed is just 400MHz. That means I never should set FSB higher than 400?? Thanks for reading all of this!
Hmmm. With those older CPU cores, the best way to overclock is by using the front-side bus (FSB), not the multiplier. People usually choose the Q6600 or a similar model because they have a lower FSB speed here; in this case, it's 1066mhz. The 1066 number comes from four separate channels working together to make the base speed of the memory (RAM) run at 266 mhz times four equaling 1066mhz total. On the other hand, the Q9xxx series has an FSB of 1333mhz. This happens when the RAM runs at a lower base speed of 333mhz and then multiplies that up to get 1333mhz. If you have RAM running at 400mhz, both the base frequencies fit right inside your memory slots (DIMMs). On your motherboard, you can try changing the FSB from 266 mhz to 333 mhz. This will speed up your CPU clock. That is the simplest way to do it. If your CPU uses a Go-stepping and you already have an overclocked version of that chip, you might not even need to change the voltage setting (vcore) because you can just set the FSB to 333 mhz or higher if your board supports it. Some motherboards let you go up to 400 mhz in this range, but getting past 333 mhz with a Q9xxx chip is hard because that chip already has such a fast bus. I had one of my old systems with a Q6600, and I just changed the FSB from 266 to 333 mhz, which boosted the CPU speed from 2.4 ghz up to 3 ghz. It was super easy.
The E7500 runs on a multiplier of 11, but the E7600 uses 11.5 and the E8600 uses 10. At a speed of 400FSB, that gives you around 4.4GHz on the first one, 4.6GHz on the second, and 4.0GHz on the third. Even at 1.45 volts (which is considered safe for overclocking), it's really hard to go above about 4.2GHz anyway because of how much heat that generates. So those higher multipliers aren't very useful here. I should mention that even at 4.2GHz, your 65w dual-core chip runs at full speed without any real boost, so you need a really good cooler if you plan to overclock the quad. Everyone loved the Q6600 because it cost less than $10 when the Q9650 was still around $40. You could even overclock the Q6600 by manually changing its chip on cheap machines like Dell, HP, or Lenovo just to 1333FSB. The expensive X48 chips were the only ones that officially supported 1600FSB, so when you got the Q9xxx models, bumping up to the next standard speed wasn't an option. It's impossible to force the memory faster than your RAM unless you use a laptop chipset. Intel does let you set the RAM higher than the CPU speed though. DDR2 handles overclocks pretty well, but the P45 chips are actually the fastest at 1600FSB right away. You might have to tweak the tRead Value manually just to get the best latency—on ASUS, it's called Common Performance Level.
Thank you. So, summary, to overclock to 4Ghz or higher, I have to choose between two options: 1/ replace DDR2 800Mhz with DDR2 1066Mhz, so the FSB limit to reach to 533. 2/ Buy these CPU with have 10 multiplier or higher: Core 2 Quad: Q6700 Core 2 Duo: E7300-7600 ( 10x – 11.5x); E8600 ( 10x); E6700 ( 10x) Pentium Dual Core: Pentium E6300-E6800 (10.5x – 12.5x) But no matter what option I choose. I always have to be careful: - The Temp always have to below 85 . - The voltage always below 1.45 for almost of these CPUs ( exclude Q6700 and C2D E6700, which the max voltage can reach to 1.5v). Is it right? Thank you for help, everyone. ^^
I've never seen a quad that stayed stable above 450, but finding a dual that hit 500+ is easy. It's much better to use a higher multiplier so the rest of the system doesn't get stressed, including the RAM. How would you cool down a 65nm quad? A Q6700 already uses 230w at 3.8GHz if you set it to the maximum safe voltage, and pushing to 4.0GHz+ isn't realistic for any 65nm chip long-term. You do have the right board to push a quad as it has an 8-pin CPU power connection and an 8-phase VRM, but you would need a custom loop to cool that down. Your board is on the S771 compatibility list so the correct quad to choose is a modded 45nm Xeon X5470 with a multiplier of 10. I'd be happy if it stayed at low temperatures like 85c, but I'm okay with 95c in Linpack as long as it stays stable. No real software will push the temperature that high anyway, so if it's still stable and under the throttling limit in a worst-case scenario then it's good to go. The Pentium Dual-Cores don't have the best dies even after disabling most of their cache. I had to lower the voltage to 1.4875v just to get one running at 4.0GHz. Yes, this is well over the published maximum but these are under $5 shipped so they can be considered expendable. General performance was about the same as a 6MB-cache dual running 400MHz and slower.