Adjusting the BCLK frequency or multiplier for overclocking an i7 990x.
Adjusting the BCLK frequency or multiplier for overclocking an i7 990x.
Hi everyone! It's been a while since I worked on the old rig. Recently, I managed to acquire a 990x for £50 via a friend who was disposing of an old PC. I've installed the CPU and everything is running smoothly at stock speed. Last night I attempted overclocking. Everything seems fine so far—I'm wondering if using the multiplier setting would be more suitable than just adjusting BCLK? My RAM is rated at 1600MHz, but after overclocking the CPU to 3900MHZ, the RAM drops to around 1503MHz, which is very close to its rated speed. I suspect this won't allow much further overclocking, though I might be mistaken. Would this pose any risks? I stress-tested it with Prime95 but stopped after about 7 minutes because the CPU temperature rose to 85°C and I didn’t want it to exceed that. Should I try resetting the overclock and then using the multiplier method for a safer outcome? I’m still using air cooling (check my name badge for details), so I can’t push the CPU to its maximum. Around 3.9 or 4.0GHz would be ideal, and I’m planning to get a Noctua NH-D14 soon. Also, the VCORE is currently in auto mode, showing 1.36V—which might be too high and contributing to the elevated temperatures. Could I manually lower the voltage for better cooling?
See my name badge for system details!
I’ve attached a screenshot of my overclocked BIOS here:
https://imgur.com/a/xM81r01
Any advice would be greatly appreciated—I’m still trying to figure this out!
Cheers, everyone.
Hello, first of all, if you're using the stock cooler and thermal paste (3- W/mK) for any reason—such as during testing—consider switching to aftermarket options.
BCLK OCs cover almost every component on the motherboard, which makes achieving stability quite challenging. You'll need to fine-tune RAM, CPU, iGPU, Vcore, VTT (System Agent Voltage), and other settings. Due to these complexities, many people advise against it.
Regarding your configuration, avoid using AUTO for CPU Ratio and RAM Frequency; set them manually. The BIOS may adjust these settings in the future for various reasons.
As for performance, it really depends. Some systems perform better with higher multipliers, while others excel with BCLK adjustments. So, testing both is necessary. In most cases, sticking to the multiplier is simpler and safer. If you're tired after a long day, go for BCLK—it’s easier. I personally tested mine on a similar setup and crashed 11 times before it stabilized.
If your RAM is rated at 1600, it should handle it. My BCLK is 152, and my RAM (rated at 1600) runs smoothly at 1620. If your RAM becomes unstable, try lowering its multiplier, using a looser timing, or increasing the voltage.
I don’t have much to say about your voltage settings since I’m unsure of the default value. Intel’s website suggests it’s normal. For reducing voltage (which can help lower temperatures), use the auto voltage (1.36) as a starting point and adjust manually by 0.01 steps at a time until stability returns. Also, avoid keeping temperatures above 90°C for extended periods; maintaining around 80°C is ideal.
Lastly, overclocking can be safe and enjoyable if you're prepared to troubleshoot common issues—like a frozen screen after startup (which often requires a manual BIOS reset). Most users end up with a restart or a freeze.
Happy Overclocking!
BCLK isn't a good option for OC, it's essentially a last-ditch effort. Opt for multiplier instead. As someone mentioned earlier, BCLK OC leads to unwanted changes and creates serious stability problems that are hard to fix, and in practice it offers minimal benefit compared to the effort.
Hi everyone, thanks a lot for your help! It seems I was correct in verifying this. I plan to try the multiplier method next. Despite a few mistakes, my old motherboard still works fine with what I tried using BCLK, even though it has two problematic RAM slots. I haven’t experienced any BSODs or other issues during my first attempt, which has motivated me to proceed with overclocking. I’ve bought the Noctua NH-D14 cooler but haven’t installed it yet because the case on the motherboard’s back needs adjustments. Once I fit the cooler, I’ll test the multiplier and update the thread accordingly. I’ve been using PCs for 36 years now, but I never dared to try overclocking before. Thanks again for your time, and I’ll get back to you soon!
Best,
K