We were going to use Intel Core 2 Duo E8400 processor to dot all i’s here, but unfortunately, we got the impression that MSI P35 Platinum Combo mainboard couldn’t work with Wolfdale CPUs at all. And what would you think if the mainboard set the multiplier to x6 instead of x9 and the processor Vcore to 1.115V instead of 1.225V on the very first boot-up? These values got back to normal after restart, but the system didn’t boot even a single time. The best we could see was a strange error message saying “The file is possibly corrupt. The file header checksum doesn’t match the computer checksum.” and then the board simply refused to work at all. However, MSI assured us that MSI P35 Platinum Combo mainboard did support Wolfdale processors, so we decided to continue experimenting.
I have to admit that the user’s manual for MSI P35 Platinum Combo mainboard describes a little bit lengthy but overall correct restart procedure after failed POST. You should try rebooting the system three times (with intervals of over 10 seconds between the attempts). The fourth time the mainboard will offer to press any key except Del and then will ask if you wish to save the BIOS settings (press Y for Yes) or load the pre-saved settings profile (press N for No). In fact the board sometimes responded after the first failed attempt already (which pleased us a lot), and sometimes reset all the parameters including the date and time to the nominal settings without even asking (which frustrated us a lot).
No wonder, since we know there are boards with impeccable WatchDog Timer technology, and boards that cannot monitor start POST at all, so you have to clear CMOS every time you over-overclock them. MSI P35 Platinum Combo mainboard seems to be somewhere in-between the two extremes, however, we have also discovered one more very unpleasant thing about it – it would occasionally freeze dead. First we experienced it when we replaced one type of memory with the other. Then it froze on us when we reset the jumpers setting the FSB speed, and once it happened even when we attempted to load the optimal BIOS defaults. When this happens, the mainboard doesn’t react to anything, Clear CMOS doesn’t help, the board powers on, but doesn’t start and the only thing that helps is to replace the CPU or the memory.
At first we supposed that MSI P35 Platinum Combo got into this catatonic stupor when we installed Intel Core 2 Duo E8400 processor, sow e decided to give it another try. To make sure that we do not provoke another stupor like that, we erased Intel Core 2 Duo E6300 overclocking data from the BIOS and loaded the optimized defaults. You can obviously imagine how surprised we were when the board refused to start Windows and produced the already familiar error message: “The file is possibly corrupt”! We rechecked all BIOS parameters, and they were normal, except for the DDR2 frequency that was set to 1066MHz being only 800MHz before. In fact there are a lot of mainboards that automatically set this frequency right away and work fine. Could it be the memory frequency? You will be surprised but MSI P35 Platinum Combo really cannot work with 1066MHz memory frequency! We couldn’t find a reasonable explanation for that, but the timings have nothing to do with it for sure, because we tried setting them manually to guaranteed correct values and it didn’t help.
So, we have almost accidentally revealed one more problem about MSI P35 Platinum Combo mainboard that may cost it performance: when the CPUs are running at the nominal speeds the memory frequency can never be set at 1066MHz. Now, however, we can explain why our initial attempts to boot with an Intel Core 2 Duo E8400 processor failed. The mainboard would set the memory frequency at 800MHz for Intel Core 2 Duo E6300 and Intel Core 2 Extreme QX6700 processors with the nominal 266MHz FSB frequency and they worked perfectly fine. However, for Intel Core 2 Duo E8400 with 333MHz FSB it would set the memory speed at 1066MHz, failed to boot and got into this “stupor” state after a few failed attempts. As we have already said, only replacing the CPU or the memory type helps get the board out of it, but what should you do if you simply don’t have an additional CPU or memory kit handy? The situation is not hopeless and you can revive the board by resetting the FSB frequency jumpers.
Unfortunately, we still couldn’t overclock our Intel Core 2 Duo E8400 processor. Even if the system loaded Windows, error messages or BSOD popped up during the first seconds of the Prime95 stability test. The CPU didn’t work at 470MHz FSB with its default multiplier, didn’t work at 530MHz FSB with the multiplier dropped to x8, although we made sure that these settings worked fine on other mainboards. Even reducing the frequency didn’t help regain stability.
1.55-1.6V that the Intel Core 2 Duo E8400 processor needs to speed up to 4.23GHz is quite high, however, we failed to get the system to run with Vcore at 1.5V and FSB frequency at 450MHz. And only at 1.4V Vcore and 420MHz FSB (420x9=3780MHz) the system worked for a few minutes instead of seconds. If we reduced the multiplier to x8, then 3780MHz frequency can be achieved with 472MHz FSB, which proved to be a good operational mode, too. So, why does the board work absolutely fine at 472MHz FSB but fails to run stably in the entire interval up to 420MHz? The resolution was very unexpected: we should disable EIST (Enhanced Intel SpeedStep Technology) in the BIOS in order to adjust processor frequency multiplier. Could it prevent MSI P35 Platinum Combo mainboard from overclocking Wolfdale CPUs?
And this assumption proved absolutely correct. 470x9 as well as 465x9 modes were very unstable, however we could get our system to work at 460MHz FSB (the mainboard always sets the FSB frequency 1MHz higher than what you have in the BIOS).
Of course, we are losing all power-saving modes if we disable EIST in the BIOS, the mainboard doesn’t reduce the clock frequency multiplier and voltage any more if there is no heavy workload. Besides, we failed to overclock the processor to its maximum like on other mainboards, but it was still way better than what we have initially achieved. High processor temperature prevented us from pushing its Vcore any further, as it rose to 76ºC during Prime95 tests. That is why we couldn’t at first start at 530MHz FSB with x8 multiplier, although we also disabled EIST – that was too good for MSI P35 Platinum Combo. The maximum we could overclock to with lowered x8 multiplier was 517MHz or 518MHz FSB (460x9=4140, 4140:8=517.5).
However, it was more than enough to finally see if the performance on MSI P35 Platinum and MSI P35 Platinum Combo mainboards drops in the 513-515MHz FSB interval. We launched the system at 514MHz, tested the memory subsystem in Everest suite and obtained pretty realistic results:
And now let’s perform the same test at 515MHz, only 1MHz higher FSB frequency, with all the other settings and memory timings unchanged:
No comments are necessary. It doesn’t matter how far your processor can actually overclock. It doesn’t matter what the maximum bus frequency is when MSI P35 Platinum and MSI P35 Platinum Combo remain operational. The truth is that it doesn’t make sense to overclock past 514MHz, because the performance will drop down dramatically in this case.
