i5 8400 Bclk overclocking

omeds

Senior member
Dec 14, 2011
646
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81
Hi forum,


I couldn't get hold of 8700k at launch so have bought an i5 8400 until later in the year. I have an ASUS Strix Z370-E motherboard that states it has 'ASUS Pro Clock Technology that enables up to 432MHz base clock overclocking'. The diagram seems to indicate a dedicated 'Pro clock' chip that I assume is a base clock generator. Am I safe to assume this means I can OC the bclk without fear of frying components??

Thanks guys
 

VirtualLarry

No Lifer
Aug 25, 2001
53,761
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Try it and see? Plenty of us are interested in any Z370 board with a BCLK generator chip that can OC locked CFL CPUs.

I've read that ASRock boards with "Hyper BCLK Engine II" support it, but it doesn't appear that the ASRock Z370 ITX/ac board I ordered does. Oh well. (I also ordered the i3-8100. Would be cool if I could get that to 4.6-5.0Ghz.)
 

omeds

Senior member
Dec 14, 2011
646
13
81
Well that's the thing, I'd like to adjust bclk without frying components.. I have NVMe drive installed etc.

On another note, I just pushed memory from 3200mhz to 3600mhz CL14 and it didn't even blink. No tweaking at all, it just works, very impressed.
 

johnny5bravoguru

Junior Member
Oct 6, 2017
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So you can run this cpu @ 4.9ghz on all 6 cores full time? This would make this a worthwhile purchase for me. What backclock are you running? I am getting the Asus Strix Z370-H which has great OC features and as I understand it, allows independent bckclock manipulation.
 

johnny5bravoguru

Junior Member
Oct 6, 2017
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0
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So far, the best I can get out of it is 4.1 single core turbo, with 2, 3, and 4 at 4.0, and 3.9 for 6 cores. Memory at 3700 cl14.
So you can run this cpu @ 4.9ghz on all 6 cores full time? This would make this a worthwhile purchase for me. What backclock are you running? I am getting the Asus Strix Z370-H which has great OC features and as I understand it, allows independent bckclock manipulation.
 

omeds

Senior member
Dec 14, 2011
646
13
81
So you can run this cpu @ 4.9ghz on all 6 cores full time? This would make this a worthwhile purchase for me. What backclock are you running? I am getting the Asus Strix Z370-H which has great OC features and as I understand it, allows independent bckclock manipulation.
Ha I wish. No it runs at 4.1, 4.0, 3.9 depending on the core count.

I wouldn't mind BCLK OCing provided that Speedstep still works.
Unfortunately I either can't figure it out, missed a setting to dsync frequencies, or 'Pro clock' isn't what I was hoping it was - like the Asrock boards that had a separate clock generator. I can only get 103 bclk out of it which seems normal.

On the plus side, it's ~8% faster than my previous 4770k oc'd in ST, and ~22% faster in MT benchmarks.
 
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Coco10

Junior Member
Oct 6, 2017
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Did it hit 4.0Ghz in all 6 cores out of the box in Turbo
? Or need adjustment from bios
 
Last edited:

PeterScott

Platinum Member
Jul 7, 2017
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40 Multiplier is for ONE core.

All core is 38 Multiplier.

I don't know how much rounding he is doing, but it sounds like all the BCLK OC he is getting 102.7 MHz (instead of normal 100 MHz).

Which is what I saw just about everywhere. Intel shuts it down if you get over 103 MHz BCLK, so the external clock doesn't do squat on locked processors.
 

VirtualLarry

No Lifer
Aug 25, 2001
53,761
8,009
126
I don't know how much rounding he is doing, but it sounds like all the BCLK OC he is getting 102.7 MHz (instead of normal 100 MHz).

Which is what I saw just about everywhere. Intel shuts it down if you get over 103 MHz BCLK, so the external clock doesn't do squat on locked processors.
The UEFI on my ASRock Z370 ITX/ac board, with an i3-8100, normally has a max clock of 3.6Ghz, 36 multi. When boosting the BLCK, the highest it will go (UEFI-enforced) is 102.7. But when you do that, the UEFI takes off a multi off the top, so your max multi becomes 35. Making the BLCK OC basically pointless.

Intel has CFL really locked down for OC.
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,574
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40 Multiplier is for ONE core.

All core is 38 Multiplier.

I don't know how much rounding he is doing, but it sounds like all the BCLK OC he is getting 102.7 MHz (instead of normal 100 MHz).

Which is what I saw just about everywhere. Intel shuts it down if you get over 103 MHz BCLK, so the external clock doesn't do squat on locked processors.
I'm not sure when it was stopped, but with Haswell and a Z board, the turbo multiplier worked for all cores on locked Haswell chips, desktop and Xeon.

Here is my 1231-V3 with all cores at 3.8 running Burn Test.

http://www.mediafire.com/convkey/40ea/o3gtne7lgxkuu3z6g.jpg

This worked with all locked Haswell chips with a turbo multiplier, such as a 4790 running all cores at 4.0
 

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