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BCLK vs cpu ratio?

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February 16, 2013 9:12:03 PM

have an i7 3930k. When I have the bclk set to 125 I can't get my ram past 1685mhz.(this is what asus did in the OC profile in bios) ....If I drop bclk to 100 and set cpu ratio to 44 then I can put my ram at 1886 which is what speed I purchased it at.

Is it better to leave a higher bclk/lower ram speed....or drop bclk to 100 and up cpu ratio and ram speed.


Confused on the difference

More about : bclk cpu ratio

a b à CPUs
a b K Overclocking
February 16, 2013 9:42:59 PM

Bench both and see the best, CPU clock is the more important so set this one first
(in my experience, higher Base clock and CPU speed will show increased ram bandwith vs faster ram)

Then determine your max Base clock and set the ram ratio the closer of the 1866mhz, then tweak voltage and timings on the ram...

To determine max base clock, minimum ratio on the cpu and memory to ensure the only thing that will fail is the chipset, not RAM or CPU related failures...

FYI: base clock is like FSB on old board, it's the speed of the chipset, it'll change the CPU and RAM speed (potentially way more like on 1155 where the HDDs and PCI-e are linked to the base clock) When it fails, i suggest to go 5-10mhz lower to ensure long terms as if you back only 1mhz, you will surely have some trouble when components will be older and the capacitors aging will show...

PS: Anything higher than 1600 CL9 is great but Auto overclock is always the baddest thing, that always put too much voltage so copy the settings and tweak them for a lowest voltage and/or even higher clocks...
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February 17, 2013 3:39:04 AM

Thanks,

By cpu clock do you mean the cpu ratio or the bclk haha.

In essence I'm assuming you're saying that it's better to have the bclk at a higher value like 125 then to have ram at 1886 instead of 1685. I followed only about half of what you said unfortunately. I'm new to overclocking and just looking for the best performance in games so if you could give me a more direct answer it would be helpful
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a c 233 à CPUs
a c 106 K Overclocking
February 17, 2013 3:56:44 AM

Do NOT overclock Sandy Bridge via BCLK. Use the unlocked multiplier, that's what it's for. Using BCLK overclocks everything including including things not ever meant to be overclocked like your hard drive and PCI-E slots. You can easily damage components by going too high with the BCLK.

RAM speed matters very little to none with Sandy Bridge/SB-E due to the chips having an integrated memory controller. You will see about a 1% increase in performance in things like video processing going over DDR3 1600. In gaming there will be no difference at all. Literally there is a 0 FPS difference in having RAM faster than DDR3 1600.
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a b à CPUs
a b K Overclocking
February 17, 2013 4:00:25 AM

By cpu clock i meant actual speed (independant of the cpu ratio or base clock) in GHZ

CPU final clock is your priamry objective over base clock and ram clock, you shouldn't compromise that speed by reducing the base clock or changing the ram ratio...

So you start determining an aproximate overclocking value for your cpu by changing the multiplier and voltage to the clock you want and then start to adjust the base clock...

When adjusting the base clock you want to find the max potential value of it (that's why you need cpu and ram at lower state) then you finally adjust the ram speed to match the closer possible to it's rated speed... You can change the ram ratio or lower the base clock with a higher ratio but keep in mind you still want the best base clock so even if you reach maybe 150 but your ram is 1700, that'll be better than 125 and 1866...

In clear your priority are CPU clock-->Base Clock-->RAM speed so the compromise you want to do is more on the ram side

As you up your fsb if you want say 4.8ghz 100*48 will do it but you can achieve it by doing 38 or 39 X 125 or 150 X 32 (150 X 32 will theorically be the fastest one)
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a c 233 à CPUs
a c 106 K Overclocking
February 17, 2013 4:05:20 AM

spawnkiller said:
By cpu clock i meant actual speed (independant of the cpu ratio or base clock) in GHZ

CPU final clock is your priamry objective over base clock and ram clock, you shouldn't compromise that speed by reducing the base clock or changing the ram ratio...

So you start determining an aproximate overclocking value for your cpu by changing the multiplier and voltage to the clock you want and then start to adjust the base clock...

When adjusting the base clock you want to find the max potential value of it (that's why you need cpu and ram at lower state) then you finally adjust the ram speed to match the closer possible to it's rated speed... You can change the ram ratio or lower the base clock with a higher ratio but keep in mind you still want the best base clock so even if you reach maybe 150 but your ram is 1700, that'll be better than 125 and 1866...

In clear your priority are CPU clock-->Base Clock-->RAM speed so the compromise you want to do is more on the ram side

As you up your fsb if you want say 4.8ghz 100*48 will do it but you can achieve it by doing 38 or 39 X 125 or 150 X 32 (150 X 32 will theorically be the fastest one)



It will also fry every component in his system............Sandy and Ivy Bridge are not Nehalem or Lynnfield.
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February 17, 2013 4:20:31 AM

I put base clock to 100, cpu ratio to 44 and ram at 1886 and core voltage at 1.350 in bios. Stress testing with prime 95 for over an hour and everything solid. max temp is 74 degrees.

anort3, the default asus OC profile automatically adjusted my bclk to 126. Why would they do this if it was unsafe and could fry my components? All I simply did was drop bclk to 100 so I could put ram at the speed I bought it for. I'm just wondering if I should get back to bclk at 126 and 1685mhz with 4.4ghz 24/7 OC or run 100 bclk @ 4.4ghz 1886 ram.

I really don't understand anything more than that haha sorry
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February 17, 2013 4:23:24 AM

Also, should I disable speedstep? Looking for max performance in games and I don't know if it'll auto downclock my cpu if it's on
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a b à CPUs
a b K Overclocking
February 17, 2013 4:36:45 AM

That's why he need to determine is max base clock before doing anything else !!!

On X79 base clock overclock is ok, that's on 1155/1156 that we have problems when overclocking the base clock (however determine it's max and you'll be ok, my max is 105, i stay there and that gets me about 4gb/s more bandwith in ram and about a 10% over a same speed overclock but at 100 base clock...)

PS: i run that for 5-6 months, 2 SSD and 2 1TB blue in raid, i don't have any data corruption or any other problems... (106 Random BSOD and 107 BSOD at startup)
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a b à CPUs
a b K Overclocking
February 17, 2013 4:38:18 AM

cheebamaster said:
I put base clock to 100, cpu ratio to 44 and ram at 1886 and core voltage at 1.350 in bios. Stress testing with prime 95 for over an hour and everything solid. max temp is 74 degrees.

anort3, the default asus OC profile automatically adjusted my bclk to 126. Why would they do this if it was unsafe and could fry my components? All I simply did was drop bclk to 100 so I could put ram at the speed I bought it for. I'm just wondering if I should get back to bclk at 126 and 1685mhz with 4.4ghz 24/7 OC or run 100 bclk @ 4.4ghz 1886 ram.

I really don't understand anything more than that haha sorry

I would run 126 1685 over the 100 and 1866, like i just wrote 2011 socket support base clock change so it's not a problem at all

Anyway, the only way to be sure it's to benchmark both and see witch one perform the best !!
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a c 233 à CPUs
a c 106 K Overclocking
February 17, 2013 4:49:24 AM

You are right. LGA 2011 does not automatically overclock everything like LGA 1155 does. My mistake. I knew anything over about 105 could be dangerous to Sandy and Ivy and forgot Intel allowed for it in SB-E. I was correct about the memory controller limitations though.
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February 17, 2013 5:22:41 AM

Thanks guys, I'll leave it at 126, 1685 and 4.4ghz.

One more thing...whenever I disable speedstep in the Bios I get "overclock failed" message at reset and have to re-enable it. I'm confused as to why this happens
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a b à CPUs
a b K Overclocking
February 17, 2013 5:32:37 AM

Surely because SpeedStep always change the voltage of your CPU, however to have a good stable overclock you'll need to disable it (in my experience in almost 90-95% of the PC that i overclocked it helps...)

However like i said, boot into windows, check with CPU-z what CPU Vcore you're running at and copy this setting (at full load) and then reduce it the much you can, when it fails, bump it up 2 notch and you'll be ok for 10 years ^^
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