Drawback to overclocking via BCLK? (X79/X99)

[MiRai]

I'm sure this has been discussed before, but I did a search for BCLK and it didn't really yield any specific threads related to Intel's -E chipsets (X79/X99). I've also Googled this, but it seems that I keep reading the same thing over and over, and there never seems to be any sort of concrete answer.

So, is there any actual, tangible drawback to using BCLK to overclock the CPU and RAM on -E chipsets?

Now, I understand that it's the base clock of the motherboard, and everything connected to it is then essentially "overclocked," but has there been any hard evidence that it's actually damaging the components attached to it, or is it just that, in theory, you could damage the components connected to a motherboard when using a higher base clock? Could the opposite of that also be true, where if we're using a higher base clock, and everything attached to the motherboard is "overclocked," would those components then, in theory, perform better, as well?

 

[Shmee]

For the most part, people just use the unlocked multipliers for their advantage, easier than X58 and cheaper for the unlocked CPUs. Now, you can use different blck straps, specifically for high speed ram i believe. Keep in mind that one thing you don't want to OC is the PCIE bus, generally doing so causes issues.

 

[Carfax83]

As Shmee said, overclocking via base clock affects the other components on the motherboard, namely the PCIe and DMI components..

Using the base clock straps locks the DMI and PCI-e buses to 100MHz via a ratio, whilst still allowing the CPU and RAM to use the faster bus..

One downside of using the bclk for Haswell-E is that you can't use adaptive voltage, which to me is the most efficient way to overclock the CPU..

 

[MiRai]

Okay, I see. I don't seem to have a 'bootstrap' option in the BIOS of my motherboard (MSI Godlike), so I'm not sure if the BCLK settings is automatically applying it or not. /shrug

I also didn't realize that I couldn't use adaptive voltage with BCLK, which almost seems like a deal breaker for me.

 

[Burpo]

"Thanks to a integrated Clock Generator, MSI motherboards support more flexible BCLK adjustments, from 100 / 125 / 167 MHz straps.

Using these straps prevents system crashing while overclocking on the edge and opens doors to achieve the absolute maximum. The MSI X99 motherboards all come with the next generation Clock Generator offering even lower jitter and power consumption resulting in even higher stability under extreme conditions."

"if you enable memory XMP at 2400 MHz or higher, your base clock will jump to 125 MHz!

Example: 125MHz x 37 = 4625 MHz (if you have XMP enabled - you will be defaulted to a 125 MHz bus)
Increase CPU voltage, though setting AUTO might work fine, we applied 1.3V on the processor to reach 4100 MHz and needed 1.4 Volts to reach ~ 4.5 GHz
Make sure your processor is properly cooled
Save and Exit BIOS / EFI"

http://www.guru3d.com/articles-pages/msi-x99a-godlike-motherboard-review,22.html

 

[Headfoot]

As Shmee said, overclocking via base clock affects the other components on the motherboard, namely the PCIe and DMI components..

Using the base clock straps locks the DMI and PCI-e buses to 100MHz via a ratio, whilst still allowing the CPU and RAM to use the faster bus..

One downside of using the bclk for Haswell-E is that you can't use adaptive voltage, which to me is the most efficient way to overclock the CPU..

I have a 5820k on an Asrock Extreme4 X99 and running with 120.1 BCLK (which is what my XMP profile for the RAM set it to) and I can use adaptive voltage still fine. I still prefer to use override mode though so I couldn't tell you what my offset would be if I were to use it

For the OP, nearly everything running off the BCLK can be set to different speeds via its own mutiplier or strap, so you dont end up overclocking everything by increasing the bus, just some things. For example, uncore/cache has its own multiplier, cpu frequency has its own multiplier, DRAM has its strap, PCIe clock has its own strap, etc. There is no draw back to overclocking via BCLK other than all the usual OCing draw backs (stability, heat, power use). It gives you more avenues of experimentation to get a higher OC. Most of the time you still get most of your OC from the CPU multiplier though as that is the easiest and most stable to increase. However, once you hit a multiplier wall you can sometimes squeeze yet more out via BCLK.

 

[Carfax83]

I have a 5820k on an Asrock Extreme4 X99 and running with 120.1 BCLK (which is what my XMP profile for the RAM set it to) and I can use adaptive voltage still fine. I still prefer to use override mode though so I couldn't tell you what my offset would be if I were to use it

For the OP, nearly everything running off the BCLK can be set to different speeds via its own mutiplier or strap, so you dont end up overclocking everything by increasing the bus, just some things. For example, uncore/cache has its own multiplier, cpu frequency has its own multiplier, DRAM has its strap, PCIe clock has its own strap, etc. There is no draw back to overclocking via BCLK other than all the usual OCing draw backs (stability, heat, power use). It gives you more avenues of experimentation to get a higher OC. Most of the time you still get most of your OC from the CPU multiplier though as that is the easiest and most stable to increase. However, once you hit a multiplier wall you can sometimes squeeze yet more out via BCLK.

I'm pretty sure you're using offset and not adaptive. Adaptive voltage runs off of the 100 bclk.

You can find out pretty easily. Use CPU-Z and see what your idle speed and voltage are. If it's not 1200MHz, you're not using adaptive..

 

[MiRai]

A bit of a delayed response due to me still messing with my new build.

"Thanks to a integrated Clock Generator, MSI motherboards support more flexible BCLK adjustments, from 100 / 125 / 167 MHz straps.

Using these straps prevents system crashing while overclocking on the edge and opens doors to achieve the absolute maximum. The MSI X99 motherboards all come with the next generation Clock Generator offering even lower jitter and power consumption resulting in even higher stability under extreme conditions."

"if you enable memory XMP at 2400 MHz or higher, your base clock will jump to 125 MHz!

Example: 125MHz x 37 = 4625 MHz (if you have XMP enabled - you will be defaulted to a 125 MHz bus)
Increase CPU voltage, though setting AUTO might work fine, we applied 1.3V on the processor to reach 4100 MHz and needed 1.4 Volts to reach ~ 4.5 GHz
Make sure your processor is properly cooled
Save and Exit BIOS / EFI"

http://www.guru3d.com/articles-pages/msi-x99a-godlike-motherboard-review,22.html

Gotcha, thanks. Browsing through the manual in the BIOS section didn't yield any results, and the descriptions in the BIOS are generally less than helpful. :\ I read that review, albeit months ago, so I should have known.

I have a 5820k on an Asrock Extreme4 X99 and running with 120.1 BCLK (which is what my XMP profile for the RAM set it to) and I can use adaptive voltage still fine. I still prefer to use override mode though so I couldn't tell you what my offset would be if I were to use it

I tested it for the hell of it the other day after reading what Carfax had written, and the machine wouldn't POST at all. I didn't even get an initial code, just a big fat 00 on the LED readout.

There is no draw back to overclocking via BCLK other than all the usual OCing draw backs (stability, heat, power use). It gives you more avenues of experimentation to get a higher OC. Most of the time you still get most of your OC from the CPU multiplier though as that is the easiest and most stable to increase. However, once you hit a multiplier wall you can sometimes squeeze yet more out via BCLK.

That's what I figured. Overclocking has its drawbacks, and those drawbacks are the same no matter what you're overclocking, or which method you're using.

 

[Headfoot]

I'm pretty sure you're using offset and not adaptive. Adaptive voltage runs off of the 100 bclk.

You can find out pretty easily. Use CPU-Z and see what your idle speed and voltage are. If it's not 1200MHz, you're not using adaptive..

It could be that Asrock has renamed the actual control, but I don't have an offset voltage option in the UEFI, only one called "Adaptive." Whether that is actually adaptive or actually offset, I couldn't tell you.

To OP:
I'd just note that BCLK overclocking becomes unstable a lot more quickly than multiplier based does. BCLK these days is most useful as an adjunct, to add a little on the top of the mostly-multiplier based OC

 

[Carfax83]

It could be that Asrock has renamed the actual control, but I don't have an offset voltage option in the UEFI, only one called "Adaptive." Whether that is actually adaptive or actually offset, I couldn't tell you.

Yeah some motherboards are like that. It's not true adaptive unless you're using the 100 bclk, and if you're using a higher strap, then it's offset.

But you could easily find out whether it's adaptive or not, by looking at the voltages. Offset adds voltage to the entire voltage range of the CPU, including idle.

Adaptive only adds voltage to the turbo frequency, so otherwise the voltages should be identical to stock.

My CPU for example has an idle voltage of 0.717v at 1200mhz using adaptive, and with C0 and C1 enabled.