help the new guy out

[PartEleven]

This forum is totally awesome, and the stickies are great, no-nonsense how-to guides on overclocking. I'm thinking of building a C2D system and overclocking it. Now the sticky on overclocking C2Ds is great, but I've still got a few conceptual questions about the process:

1) The guide mentions about bumping voltages up, then lowering them while still keeping your system stable. What's the point of this? How does voltage affect CPU clock speed and why would you want to lower the voltage as far as possible?

2) How does RAM fit into the equation? I understand you need stable running ram, but why are lower timings better? What makes 4-4-4-12 better than 5-5-5-15? And just how does RAM affect CPU overclocking anyway (other than stability)?

3) How does the FSB affect RAM? Why do we want a 1FSB:1RAM ratio, and how does this ratio affect RAM speed?

4) What about lapping the CPU/heatsink? Would this be neccessary for a mild overclock (~3.0GHz)?

5) I heard that overclocking technically lowers the lifespan of my components. Granted, these things are rated to last longer than most enthusiasts will use them for (10 years), but I want to make sure my system remains stable for a long time, as my other family members will be receiving it as a hand-me-down in the future.

6) The guide doesn't address the new models e6420 and e6420. Is there anything different about these processors that I need to know? Are they really just simply e6300s and e6400s with an extra 2MB of cache?

7) I'm looking at getting the e6320 or e6420. I'm leaning toward the e6320 because that overclocks as well as any other C2D and is a bit cheaper. From an overclocking perspective, is there anything that the e6420 brings other than higher clock speed? If so, is it worth the price increase to get the e6420?

I know it's a massive list of questions, but this is my first attempt at overclocking and I want to go in knowing why I'm doing things, rather than just blindly following instructions. Thanks for hearing me out.

 

[mythos]

1) Voltage gives the CPU more "juice", if you will. It's more complicated than that, but that's basically it. The tradeoff is more heat - Power = V x I, therefore, increase the V, increase the P - which is measured in Watts, or equivalently, as the rate at which a charge carrier loses energy. As your current flows through a resistor (your CPU), the resistor heats up according to Pxt (Power x time). Thus the heat in your CPU is an equilibrium of the voltage you give it, and how fast you can remove the resulting heat. If your CPU heats up too much, bad things happen, much like anything else - the lower you can keep the voltage, the lower your failure rate.

2) Timings on the RAM indicate the latency (in clock cycles) of access, as defined by different parts of the matrix (row, columns, etc). Obviously, the less time it takes to access a certain part of teh memory, the faster you can get it to the CPU, and the faster everythinn else will go. Look up Wikipedia for a more detailed explanation of what the numbers mean. This is a distinct measure of performance from the frequency, which is measured in MHZ (how many actions per second can be performed), and the data rate (ie DDR, DDR2) which determines how many actions per clock cycle can be performed. All work together to determine your RAM's performance

3) FSB doesn't affect RAM; most MOBOs allow you to set their frequencies independently. However, having a "divider" to bring the RAM frequency in line with the FSB frequency introduces some latency into the equation which seems to - at least in the case of Core2, which isn't so dependent on bandwidth - offset any gains you might see by increasing your RAMs frequency above that of the FSB. Thus, 1:1 = good.

4) No. Lapping creates a smoother surface which increases the efficiency of heat transfer between the CPU and the heatsink. Makes about 5 degrees of difference max, depending on who you ask, and only necessary for really squeezing every last drop out of your setup.

5) As long as you keep voltages within limits, your system should be more than fine and last you beyond your next upgrade

6) Yes, exactly the same without 2MB of cache disabled. 5% difference from the lower cache models, give or take - ie statiscally insignificant.

7) E6420 brings higher clock speed because of higher multiplier (multiplier x FSB = clock speed). Thus, you will be able to achieve the same overclocks with a lower FSB setting. I would say go for teh 6420 - you can do a nice and relatively easy 400MHZ x 8 = 3.2GHZ which is much harder to achieve on the E6320.

And in conclusion:
Learn to google and wiki as most of the answers to your questions are right there at your fingertips!

 

[PartEleven]

Wow that was a great detailed reply. Just what I was looking for: a focused answer that covers all of my questions . I have tried googling and wiki but it was hard to get clear, concise answers. Then it led me to this forum. Thanks for sharing your knowledge!

 

[mythos]

Np, actually, I remeber how long it took me to piece together all this information so I'm always glad to help out with specific questions

 

[PartEleven]

Do you know how Vista affects overclocking? Would it be incompatible with some of the diagnostic tools? And while we're on it, would it be better to overclock in XP, then reformat and install Vista after the system is stabilized?

 

[mythos]

I'm not an expert on vista so someone might correct me if I'm wrong, but I don't think the OS has anything to do with overclocking. Some of the diagnostic tools for stress-testing etc might be incompatible, I don't know, but you don't need to overclock in xp first or anything like that as adjustments you make happen in the BIOS in any case.

 

[James10]

As far as I know, the OS has no impact on overclocking. As for compatible diagnostics programs, TAT, CPU-Z, Prime95, Orthos, SpeedFan and CoreTemp all work fine on my Vista machine. Along with 3DMark06 and SuperPi, the programs I use for benchmarking.

Just do the OC with Vista installed, it won't make any difference.

 

[PartEleven]

Thanks for all the help. I made another post in the cooling subforum, but I didn't get much response there so I'm reposting it here since I've got a thread going already:

I'm having a problem deciding which heatsink to get. Can anyone recommend a value heatsink that has decent cooling capacity? So far I'm looking at two candidates:

AC Freezer Pro 7 - Lots of people recommend this as a great bang for your buck, but I have noise concerns about that one. Noise is a pretty big factor for me.

Scythe Ninja - Rave reviews and even more recommendations. Expensive though, especially if you want it operating with a 120mm fan.

For the sake of noise, I'm currently leading towards the ninja. To keep costs low, I might use it as a passive cooler without the fan. Would this have problems cooling a e6420 OCed to ~3.2 ghz without a fan? Obviously the ninja is hands-down the better cooler, so please remember to take price into the consideration.