Unlocked Haswell CPUs + H-series mobos Overclocking?

[Brian_PCguy]

>Question:

What exactly is the difference between a motherboard that supports overclocking and a mobo that does not?

>Misc. info:

I own an MSI H97 PC Mate motherboard and a 4790K. The CPU is, of course, very powerful and does not necessarily need to be overclocked for what i'm using it for (gaming); but as a person who has experience using other mobo manufacturer bios interfaces (Gigabyte B85 - another mobo chipset considered locked), I don't understand why H-series boards are considered "locked" or "not overclocking supported". The MSI H97 bios interface allows for changing the core clock ratio, as well as voltage settings, among other OCing-esque features. I've successfully overclocked my Pentium G3258 up to a stable 3.9ghz (i'm confident I could have OCed it further, but never tried). What am I missing? This bios supports OCing in every way imaginable. Why do so many people claim that certain series of motherboards do not support overclocking?

 

[Petrossa]

According to Intel, they're not "supposed to" allow overclocking on anything else than a Z-Series board.
But the manufacturers, listening to what the consumer wants, have made their own tweaks on these boards to allow some form of overclocking.

 

[Eximo]

Z97 - offers lots of different BIOS options for configuring a system and overclocking down to a low level. Particularly CPU frequency multipliers. (And you need an unlocked CPU to take much advantage)
H97 - offers most of the major features of Z97 without these complex configuration options.

As you go down the product line up you start losing features and connectivity options.

For Haswell, there is not much you can do with an H97 board, you are limited to slightly overclocking with the BCLK. 100x40 or 100x44 for a 4790k, you might manage 105 on the top end and get just under 4.5Ghz. Not really worth it with that particular CPU anyway, it is already overclocked effectively.

The newer Skylake chipsets and CPUs left a little loophole and brought BCLK overclocking back for non Z class boards. The motherboard and CPU no longer have to rely on the same clock, so the CPU can be run at a different BCLK allowing effective overclocking without having access to the frequency multiplier.

Other more simpler techniques, such as forcing the Maximum boost multiplier at all times have always been an option.

 

[AJ Kenway]

>Question:

What exactly is the difference between a motherboard that supports overclocking and a mobo that does not?

>Misc. info:

I own an MSI H97 PC Mate motherboard and a 4790K. The CPU is, of course, very powerful and does not necessarily need to be overclocked for what i'm using it for (gaming); but as a person who has experience using other mobo manufacturer bios interfaces (Gigabyte B85 - another mobo chipset considered locked), I don't understand why H-series boards are considered "locked" or "not overclocking supported". The MSI H97 bios interface allows for changing the core clock ratio, as well as voltage settings, among other OCing-esque features. I've successfully overclocked my Pentium G3258 up to a stable 3.9ghz (i'm confident I could have OCed it further, but never tried). What am I missing? This bios supports OCing in every way imaginable. Why do so many people claim that certain series of motherboards do not support overclocking?

In the past, Z series boards and "K" SKU CPUs are the only pair unlocked for overclocking. Since the G3258's release, motherboard manufacturers enable overclocking to non-Z series boards because of the growing demand for budget boards that can overclock due to the release of the so-called Pentium-K. And think about it, buying a $72 chip and then buying a $100+ motherboard just to overclock a dual core is just outright stupid right? Anyways, H81, B85, H87, H97, Z87, and Z97 are all separated by number supported features so don't worry about it.

 

[Eximo]

Odd, I was watching Gundam Wing just yesterday.

Not really something Intel had planned, they released the unlocked G3258, but haven't had a follow up chip yet. So no Skylake unlocked Pentium.

It was the board manufacturers that tweaked designs and BIOS to get B and H class boards to be capable of handling an unlocked chip.

1st Gen X class (LGA1366) chips were all overclockable and there were something like 10 SKUs available in that class. Each chip had a top end multiplier, but the BCLK could be taken to extremes since it didn't effect the motherboard. These days they make 3 workstation K/X class CPUs, and 2 K class on the consumer socket each generation, and that is it (with the exception of the Pentium)

AMD keeps most of their line-up overclockable, and Intel has done it this time around with Skylake in a very similar fashion to the 1366 chips, an unganged BCLK.

Prior to the Intel Core series, pretty much all Intel chips, and x86 chips in general, could be tinkered with as long as the motherboard had multipliers that went high enough. I recall taking 25Mhz chips and running that at 36+ Mhz, which was a considerable jump back in the day. They even made some ludicrous chips with hard overclocks, like a 125 Mhz chip for a system that came with a 33Mhz chip.

 

[lodders]

Yes, you can overclock with a H series motherboard.
Yes, this feature was a change that was introduced for the pentium G3258.

Now, here's the thing.
The little square blocks on the motherboard next to the CPU are the VRM power phases.

On an overclocking motherboard, there are more VRM power phases, and they have heatsinks on them to keep them cool. This allows them to provide stable power to an overclocked CPU running well above TDP rating.

On my budget motherboard, I have VRM which were designed to run a i7 4770 at stock speed, and no more than that.
The VRM on my mobo work best with a stock cooler, because the air from the cooler blows across the VRM.
Some cheap H81 motherboards VRM will overheat if you run an i7 at 100% load on them.
According to a review I read, Asrock H81-M are also capable of running an i7. Sounds like your mobo is too.

BUT I don't have an i7, I have an i5. It doesn't have hyperthreading, so it uses less power than an i7.
So I can overclock my CPU to 4.2GHz at 1.14V on the stock cooler without overheating either the CPU or the VRM.
To go faster would require more Vcore. This would overheat both my processor and my motherboard.

 

[AJ Kenway]

Odd, I was watching Gundam Wing just yesterday.

Not really something Intel had planned, they released the unlocked G3258, but haven't had a follow up chip yet. So no Skylake unlocked Pentium.

It was the board manufacturers that tweaked designs and BIOS to get B and H class boards to be capable of handling an unlocked chip.

1st Gen X class (LGA1366) chips were all overclockable and there were something like 10 SKUs available in that class. Each chip had a top end multiplier, but the BCLK could be taken to extremes since it didn't effect the motherboard. These days they make 3 workstation K/X class CPUs, and 2 K class on the consumer socket each generation, and that is it (with the exception of the Pentium)

AMD keeps most of their line-up overclockable, and Intel has done it this time around with Skylake in a very similar fashion to the 1366 chips, an unganged BCLK.

Prior to the Intel Core series, pretty much all Intel chips, and x86 chips in general, could be tinkered with as long as the motherboard had multipliers that went high enough. I recall taking 25Mhz chips and running that at 36+ Mhz, which was a considerable jump back in the day. They even made some ludicrous chips with hard overclocks, like a 125 Mhz chip for a system that came with a 33Mhz chip.

I know this is out of topic but, do you know where I can buy/download Gundam Wing? XD

 

[Brian_PCguy]

You have all been super helpful! I appreciate the quick and thorough responses.