View Single Post
Old Aug 7, 2008, 09:46 PM   #107
AMD Overclocking Guru
Join Date: Apr 2003
Location: United States Searching for the airspeed velocity of an unladen swallow...
Posts: 238
Psychlone is still being judged by the masses


Now then, here is what I do when beginning a new overclock:
(We're going to try to find the limit for your motherboard's HTT)

Drop the CPU Multiplier to it's lowest setting
Drop the HT Link Speed to it's lowest setting
Drop the RAM divider to it's lowest setting

Begin by raising the HTT (CPU Frequency) in 5 - 10MHz increments - rebooting to POST (Power On Self Test - it's the very first screen of text in black and white that you see when you first start your computer from an OFF state) in between each change - until it wont POST (Power On Self Test) - note the number as you've just found your motherboard's maximum HTT. This is important, as your motherboard really is a major determining factor on just how far you can overclock your CPU/RAM and other peripherals. (we’re lucky, our A8R32-MVP is proven stable at 400HTT, but not *all* of them will do that, and most other boards won't even come close!!)

Drop it down to a comfortable stable level decided on from the equation above.
(yep, we're going to be using that equation *a lot*, so just get used to it!!!) - I'm going out on a limb by saying I'd try for the 280 to 300MHz HTT range...assuming your maximum HTT is high like mine was at 400MHz.

Raise your CPU Multiplier (using the equation) to no more than 10X, reboot and see if it will POST with the HTT from above...if not, reduce the HTT *OR* raise the voltage in .1V increments until it will, keeping in mind to keep an eye on the CPU temperature...DO NOT GO HIGHER THAN 1.55V!!!

(this really becomes nothing more than a balancing act at this point - and it takes time...have patience, take breaks - if you get too frustrated, stop for 10-15 minutes and do something else in a different room...I'm not kidding! I've been soooo close to putting my foot all the way through my case that it's not even funny, so I *know* what I'm talking about - TAKE BREAKS! - oh, and try not to drink alot of coffee )

If you've made it this far, you've just found a *comfortable* level from which to the hard part begins!

Raise ALL your RAM latencies to 3-4 notches above stock - in your case, straight down the list from my BIOS linked here: My A8R32-MVP BIOS Breakdown
3,13,6,6,6,12,13,5,15.6,9.5,12, 2T
Leave your voltage where it is (don't go higher - the BIOS text goes red for a reason!) - Later on, you can adjust it up to 2.85V, but you will not need it to be even .01 higher - the XMS aren't rated for higher voltage, and with them specifically, that's usually the point of diminishing returns.
Now, starting with the SECOND one (tRAS), drop it one notch and reboot to POST (and I *mean* [1] notch at a time - you do more than that, you'll find yourself resetting your CMOS twice a much as you're already going to!!!!), repeating until it will not pass the POST, clear the CMOS if you have to, and raise that one value one notch.
Do the same for ALL the latencies (rebooting to POST in between EACH AND EVERY CHANGE) - leaving tREF at 15.6, Read Preamble at 9 and ASYC Latency at 10 (just don't go lower on those for now...)
This is a *very* long and arduous process, but the benefit will be more than worth the effort you put into it!
Once you've made it this far, try changing the CMD ADDR Timing to 1T and see if it boots all the way into Windows - if not, change it back to 2T or loosen up the last 7 timings (all at once) and set the CMD-ADDR Timing to 1T and boot into Windows - if it doesn't do it, just leave that SOB at 2T and call it good. (this can really be a deal breaker for you - it's a gamble on high MHz with tight latencies and loose 2T CMD or high MHz with loose latencies and tight 1T CMD- with the tight latencies along with 1T CMD being optimal on both sides - for the most part though, a 1T CMD with *fairly* tight other latencies beats more than *fairly* tight other latencies with a 2T CMD rate. (get that? - I might have confused's getting late for me )

After you've found all the lowest latencies for the *comfortable* overclock, you can begin to see if there's any more...
By raising the CPU voltage, (NEVER HIGHER THAN 1.55V) you can increase stability in your overclock - but it comes at a great price - HEAT. If your CPU gets above 50*C under full load (should be in the 30-35*C range for idle - but load temps are the most important!), you need better cooling, or need to settle on an overclock that utilizes less voltage (which means less HTT and/or higher multiplier and maybe even a different divider)
If your temps are good (~50*C or below at FULL LOAD) then you can start experimenting with the Overvolt option. By enabling the +100mV option, you're effectively giving your CPU .078V more (ASUS has a bug in their overvolt - it's not really .1V as measured with a multimeter, it's more like .078V and the +200mV is more like .174V instead of .2V) - So, you can see that if the mobo tops out at 1.5V for your CPU (ASUS voltage regulator - it's a good thing for people that don't know what they're doing!) - by enabling the +100mV Overvolt, you're effectively giving the CPU ~1.58V, and with the +200mV, it would be roughly 1.67V - Again, WATCH YOUR TEMPS!!!

Now, last thing you'll have to test is your HT link speed...most motherboards aren't capable of much over 1000MHz (1000MHz in EACH of 2 lanes is what it really is, but we only talk about one direction when we speak of it in the BIOS...on the motherboard box it says 2GHz - 1000 up and 1000 down) - BUT, I have proven the A8R32-MVP Deluxe stable at just over 1500MHz (1500up AND 1500down) - there isn't a motherboard out there aside from ours that is capable of that! - But, they all differ...I've seen some A8R32-MVP's that struggle to reach 1100MHz, and another that is barely unstable at 1600MHz - and everything in between.

You'll want to use the equation above to find out where you *should* be, and then use the equation to see if you can go the next step higher (i.e. 3X to 4X to 5X) - you'll know when it's not stable at that speed when it BSODs (Blue Screen Of Death or reboots instantly). - For now, try to keep it at around 1000MHz and after you're comfortable with testing further, try it.
The secret for getting a higher MHz throughput out of the HT is because of the chipset and the options for it.
I enable the Overvolt to 1.5V for ALL the Northbridge options, and enable the Overvolt option for the Southbridge as helps in the stability for higher bandwidth - But you've GOT to pay attention to your motherboard temp now! Mine's sitting at 35*C right now, and doesn't really get much higher - this is due to adequate case cooling, which I suggest you definitely follow up on!!! (since the Northbridge on the A8R32-MVP Deluxe is passive, it really relies on good airflow around it to keep it cool! - if at any point you feel uncomfortable about the NB reaching into the mid 40*C range, you may want to check into an active cooling, or perhaps just removing the HS assembly and replacing the ASUS thermal gunk with a nice fresh layer of Arctic Silver5 or Ceramique)

Under NDA
Under NDA
4 X 2048MB (Under NDA)
5970 Engineering Sample
7 X WD 500GB 7200RPM 16MB Cache SATA2
HP DVD1040
X-Fi Fatal1ty Extreme Gamer w/ Creative Gigaworks S750 7.1 Surround
OCZ GameXstream 1010W
CoolerMaster COSMOS S *Modified*
(Sorry guys, I can't talk about what's in my system, so don't ask)

Psychlone is offline   Reply With Quote