i5-3550 BCLK Overclock Results = Stable?

[Jerenny]

Hey guys, so I just got my new MSI Z77A-G41 motherboard, it's not the best but for right now it's getting the job done absolutely fine.

I just installed this motherboard in yesterday and the first thing I went into is how to OC my non K processor considering no overclock is possible on my old motherboard (H61 chipset).

Then I read about BCLK overclocking and how it could screw everything up, so I didn't go that far with it. Right now, it's at 106.6MHz, and I know many many people consider that extremely high, as a lot say 103MHz is the best, but I think it's stable. What do you guys think? I ran Heaven Bench on Ultra and LinX at the same time as I was asleep.
These are the results after I woke up:

Does that mean it's pretty much stable?

 

[Yuriman]

I'd watch for errors on your hard drive, corrupted data, if I remember correctly it was mostly the SATA controllers that didn't like being run out of spec.

 

[Headfoot]

I'd watch for errors on your hard drive, corrupted data, if I remember correctly it was mostly the SATA controllers that didn't like being run out of spec.

I seem to recall that the PCIE bus would be cranky too, but yeah I thought it was primarily the SATA controllers.

Test out the overclock by doing a variety of your typical activities: web browse, play games, use whatever productivity software of your choice. I recently discovered instability in an i5-2400 at 105 BCLK only while playing certain games (and not even the most intensive games, I think it was League of Legends or something like that). Dropped it by 1 and it was ok, has been running like a champ for about 3 months now with 0 issues.

 

[BSim500]

Good job. As others have said, the problem with BCLK overclocking is not CPU stability but "silent errors". Basically, you're overclocking everything attached to the PCI-E bus including the SATA chip/bus, which can increase the likelihood of "silent errors" (data which appears to be written OK but throws up a CRC error at a later date when read back). That's the main reason a lot of people don't recommend it.

I have a "locked" non-K i5-3570. Technically it can be pushed to 4.41GHz with max 42x mult (3.8GHz Turbo + 4-bins limited OC) * 105Mhz BCLK, but I'd rather stay safe and limit it to 4.2GHz (100MHz BCLK).

Your i5-3550 should be capable of 4.1GHz (1-2T) / 4.0GHz (3T) / 3.9GHz (4T) on a Z77 motherboard. Make sure you enable "Multicore Enhancement" (or whatever it's called on your mobo if it supports it - might be "Enhanced Turbo"?) and you could potentially get 4.1GHz (under any load) without having to resort to OC BCLK. Stable +800MHz multiplier OC vs risky +1GHz with potential data corruption. I'd stick with the former to be honest.

 

[Jerenny]

Good job. As others have said, the problem with BCLK overclocking is not CPU stability but "silent errors". Basically, you're overclocking everything attached to the PCI-E bus including the SATA chip/bus, which can increase the likelihood of "silent errors" (data which appears to be written OK but throws up a CRC error at a later date when read back). That's the main reason a lot of people don't recommend it.

I have a "locked" non-K i5-3570. Technically it can be pushed to 4.41GHz with max 42x mult (3.8GHz Turbo + 4-bins limited OC) * 105Mhz BCLK, but I'd rather stay safe and limit it to 4.2GHz (100MHz BCLK).

Your i5-3550 should be capable of 4.1GHz (1-2T) / 4.0GHz (3T) / 3.9GHz (4T) on a Z77 motherboard. Make sure you enable "Multicore Enhancement" (or whatever it's called on your mobo if it supports it - might be "Enhanced Turbo"?) and you could potentially get 4.1GHz (under any load) without having to resort to OC BCLK. Stable +800MHz multiplier OC vs risky +1GHz with potential data corruption. I'd stick with the former to be honest.

I was going to try and do that, disabling turbo core and simply setting the multiplier to x41, but setting the multiplier above 39 does nothing, it acts as if it's still on 39.

 

[BSim500]

I was going to try and do that, disabling turbo core and simply setting the multiplier to x41, but setting the multiplier above 39 does nothing, it acts as if it's still on 39.

Yes, the "+4-bins limited OC" feature of Ivy & Sandy Bridge's need Turbo Boost ON to work properly. There should be another BIOS setting however called "Enhanced Turbo" which may force 4.1GHz under all loads. It's mentioned in your manual on page 2-12. Double check to see if it's enabled.

Edit : You also need Turbo Boost ON and multiplier 41x. If it works you should see 41x under all loads. If it doesn't, you'll see the multiplier fluctuate between 39-41x depending on how many cores are loaded at any one time. Try running Prime with only 1-2 threads and see if it says 41 then.

 

[Jerenny]

Yes, the "+4-bins limited OC" feature of Ivy & Sandy Bridge's need Turbo Boost ON to work properly. There should be another BIOS setting however called "Enhanced Turbo" which may force 4.1GHz under all loads. It's mentioned in your manual on page 2-12. Double check to see if it's enabled.

Edit : You also need Turbo Boost ON and multiplier 41x. If it works you should see 41x under all loads. If it doesn't, you'll see the multiplier fluctuate between 39-41x depending on how many cores are loaded at any one time. Try running Prime with only 1-2 threads and see if it says 41 then.

I'm not sure if it doesn't work or if I'm doing it wrong. Do I need to put the multiplier back to Auto for it to work? It was on 39, I turned on both Turbo Boost and Enhanced turbo, logged into Windows and instantly ran both LinX and CPU-Z. Core clock stayed at 3900MHz the entire time.
EDIT: I also brought my BCLK back down to 100 when doing this.

 

[BSim500]

I'm not sure if it doesn't work or if I'm doing it wrong. Do I need to put the multiplier back to Auto for it to work? It was on 39, I turned on both Turbo Boost and Enhanced turbo, logged into Windows and instantly ran both LinX and CPU-Z. Core clock stayed at 3900MHz the entire time.
EDIT: I also brought my BCLK back down to 100 when doing this.

Set multiplier to 41 in the BIOS (manual), then try LinX (first with 4 threads, then 1 thread) whilst monitoring in CPU-Z.

 

[Jerenny]

Set multiplier to 41 in the BIOS (manual), then try LinX (first with 4 threads, then 1 thread) whilst monitoring in CPU-Z.

Still nothing =/ I took a picture of my BIOS settings so maybe you could help me out more..

When I run LinX with those settings, HWiNFO still shows all cores running at max of 3900MHz.
What's really weird is that in the top right of BIOS, you clearly see the 41 multiplier working fine, but when I get to Windows, it says otherwise.

 

[BSim500]

When I run LinX with those settings, HWiNFO still shows all cores running at max of 3900MHz. What's really weird is that in the top right of BIOS, you clearly see the 41 multiplier working fine, but when I get to Windows, it says otherwise.

Hmm. Maybe Enhanced Turbo simply isn't working with that particular chip? I've seen that before with some boards being a bit finicky. Do you still get 3.9GHz when you go to LinX Settings -> Number of Threads = 1? In any case, a +3.9GHz Ivy Bridge i5 is still more than fast enough to run pretty much every "next-gen" game out there. And you could always risk a slight +2.5-3.0% BCLK to take it to 4GHz?

 

[Jerenny]

Hmm. Maybe Enhanced Turbo simply isn't working with that particular chip? I've seen that before with some boards being a bit finicky. Do you still get 3.9GHz when you go to LinX Settings -> Number of Threads = 1? In any case, a +3.9GHz Ivy Bridge i5 is still more than fast enough to run pretty much every "next-gen" game out there. And you could always risk a slight +2.5-3.0% BCLK to take it to 4GHz?

I believe I found out how to do it, I had to turn on Enhanced Turbo AND adjust the CPU settings to have each turbo core ratio set to +4 bins. But what sucks is it's only +4, meaning that since core 4 has a max turbo of 35, while underload, I believe each core runs at a multiplier of 41x, but I can't put any type of BCLK OC on it because it barely does anything. still 106BCLK on top of that only gives me a 60MHz increase from 100BCLK. Multiplier still shows as x39 in CPU-Z.