I recently had the chance to get my hands on an Asus Maximus II formula motherboard very cheaply form a friend. In my 3rd PC I have had an Asus Striker II Formula motherboard which I've had since I built it. That Mobo was always a bitch to overclock with as it would refuse to go higher than 400mhz FSB, bit of a shame really because I think I have one of the best E8500 cpus around which can boot up at 3.8Ghz (highest speed achievable on the Striker II) at a core voltage of just 1.08V! So naturally I couldn't resist going to a better motherboard and pushing the CPU to it's limits when the opportunity arose. Any way, the installation went well and I'm very impressed with the board especially with it's appearance. It looks far more modern than it is with a red white and blue colour scheme with matte black PCB and cooling. Much better than the Striker II formula's bare copper cooling. I've been fiddling with it for two days now trying to get the highest overclock possible but I've hit a brick wall at 4.35GHz. No matter what I do I can not get the system stable at anything higher than a 458MHz bus speed. Literally it's totally stable in prime95 at 458MHz with the 9.5 multi (4.35GHz) with a core CPU voltage of just 1.29v but it crashes in prime 95 in the first 2 minuets at 459MHz even if I raise the CPU core voltage all the way up to 1.45v. I've tried raising the PLL, NB and SB voltages, lowering the multiplier and raising the FSB, keeping memory at the lowest settings all to no avail. Now here's the really strange thing, I swapped the E8500 for an E8600 I had lying around in the hope that it's higher multiplier would give me a better overclock. Only I couldn't get that stable even at 4.4GHz with an FSB of only 440mhz, and I know that chip is capable of 4.5Ghz at least as I had it in a different system. So I don't think it's to do with the FSB but rather the final MHz of the CPU. It's so strange as I can boot to windows fine all the way up to 4.9Ghz but I can't get it stable. Is there something I'm missing here? I just don't get it. This has never happened to me before. I wondered if there were any 775 gurus still out there that could help me. It think It's such a shame because I know this CPU is capable of so much more. I'm using the latest 2302 bios by the way. Any way, here are some screen shots:
I've given up trying to raise the CPU any higher and I focused on the ram instead. I managed to tighten things up a bit: This has had a surprising effect on my minimum FPS in skyrim. It's gone from 43 fps to 47 fps just for a few extra MB/s memory bandwidth. I use a specific location to test my minimum FPS, that's at the very top of the steps in Whiterun on the way to Dragonsreach looking down at the rest of the city. It's the only place which really taxes the CPU in my experience. Otherwise I can walk around the city at a constant 60fps.
Goggle over clocking HOLE on wolfdale, I'm pretty sure I seen a pew posts about this. They can be jumped over if it is so.
http://techreport.com/review/13815/a-beginner-guide-to-overclocking/2 Check that out. The thing is that increasing your FSB beyond the official specs (past 400 MHz) also affects the PCI / PCI-E frequency. So, if your motherboard allows that, lock your PCI / PCI-E to their nominal frequencies first. Otherwise your system will become unstable due to "overclocked" PCI bus. Also, the memory frequency depends on the FSB and to my recollection the memory freq needs to be equal to or greater than the FSB freq (actual frequency, not effective). Meaning you cannot manually choose a lower memory freq than your FSB freq is. So either use the method given in the article, ie choose the FSB-to-memory ratio so that increasing FSB doesn't push your memory beyond it's nominal frequency, or use modules that have a high enough frequency for your wanted FSB (= DDR2 1066 / 1200).
Perhaps prematurely, I gave up trying to overclock on this board and swapped it back over for my old Striker 2 Formula as no matter what I did I never seemed to get it stable. I managed about 4.2Ghz but I didn't think it was a worthy enough improvement over 4Ghz and Windows actually boots up faster on the Striker 2 for some reason which is more important for me as I mainly use this PC for browsing the web. I feel I've learnt allot more about overclocking from the experience though. I went back to the drawing board and tried overclocking on the Striker 2 again and found out if I raised the "1.2v HT Voltage" it finally allowed me to break the 4GHz wall and I achieved a stable overclock of 4.3GHz. The CPU core voltage is a little high at 1.375v but I believe given enough tweaking time I could bring that down. At the moment though I tested it on Prime 94 blend for 4 hours (more than enough for me) and Intel burn test at maximum for 40 passes. The striker 2 doesn't perform as well as the Maximus 2 in games though and I get a minimum of 44fps in skyrim. Must be the memory controller. I really do wonder why I do these things sometimes. I hardly ever use this PC for gaming and I have 2 other PCs that are more powerful, but it just bugs me to know that it could perform better than it is.
It's a very demanding area. Even my i5 with 4 times the memory bandwidth and 5 years worth of architecture improvements only manages an absolute minimum of 69fps in that spot.
This is really fascinating. Just of funsies I under clocked my ram on my i5 PC to 800MHz This dropped the memory bandwidth on AIDA64 down to just under 12GBs on read write and copy which is just over what you would expect from a well tuned socket 775 PC. At the same location in Skyrim the minimum FPS dropped from 69FPS down to 45FPS!! Everything else was the same, the CPU was still running at 4.4GHz yet it lost 24fps just from memory limitations.
400mhz x2? or 1600mhz? Because the first one is literally cutting off your leg and then being surprised a wheelchair is slower than feet.
I remember having some hard time over 450mhz, it was mostly memory speed latency vs higher fsb.. Its mostly higher performance level fault and that ruined the point of higher fsb, got lower memory bandwidth output and all tests ran slowerc1::nerd: This here helped a bit, lots of voltages/memory info and various benchmark tests, although its Gigagbyte namings specific.. http://home.exetel.com.au/seasalt/Overclock.html http://home.exetel.com.au/seasalt/overclock/compare2.png
Ram was running at 800MHz effective speed. But I think it makes a valid point because most socket 775 PCs had RAM running at those sorts of speeds. I'm just surprised at how much of an impact it has and it makes me wonder just how much of the CPU performance gains since the core 2 have been down to just memory bandwidth and not actual improvements in architecture. I believe to truly compare CPU architecture you have to get them on a level playing field. So same speed and same memory. Unfortunately you cannot get a 775 CPU to have 37GB/s memory bandwidth so you have to bring Haswell down to 775 levels. However, I am aware that this rather defeats the point as you would be bottlenecking both CPUs with low memory bandwidth. This is showcased perfectly by my test as both CPUs operating at around the same frequency with similar memory have about the same minimum FPS. Unfortunately a true comparison can never be achieved however.
Just ran a few more test and things like CPUmark99 and SuperPi are not affected by the lower bandwidth which is to be expected. However a select number of games are. I've just ran Star Trek Online and I'm getting similar FPS as I get in my Q9650 PC.
