Overclocking Xeon E3 1245 v3

[JiriT]

Hi guys,
I work in CG industry, so I have all my rigs built for performance and stability. I have one rig purely for CPU rendering. I have Xeon e3 1245v3 there and it is just a great procesor. No 18 core, but it does the job very well + very low heat output.

I am a tinker, so I said to myself - lets try to mess with it.
I was able to achive BCLK at 107MHz and to set the multiplier using some asus feature in bios to be 38 during all core load instead 36 (I synchronized the maximal multiplicator for one core to be at all cores, so normaly it would be like 1core x38 and 4core x36, but i have 1core x38 and 4core x38 as well)

With all of this I was still able to lower the VCore (-0,025) and some other voltages. But whatever I do (making voltages higher etc.) I can´t get BCLK higher. At 107 it is perfectly stable (i rendered for allmost a wekk 24/7, CPU stressed like hell and no problem), but when i set BCLK to 108 it doesnt even post and i have to clear CMOS.

I have great temps and a lot of room to increase voltages and temps, so is there any possibility to get BCLK higher?
And how does the BCLK strap works? I cant find it in my BIOS thou I have Asus z97 gryphon armor edition (yea, why to buy mobo for overclocking when you have xeon, i heard that and i have my reasons) where it is supposed to be. I didnt get answer whether it hase something to do with fact, that my xeon is non-K or not.

And yes, I know that Xeons are not meant to be overclocked, but even with the setings mentioned above, I get 13% boost in realword performance - I have faster rendering and lower temps than at stock.

Ty for help

P.S. Since I bought my first Xeon, I felt in love with it. No more i7, always just Xeon.

 

[JiriT]

And the temps that are shown are no more valid. Since the awful heats that killed half the population in my country passed, I have lowered them about 8-10 degrees.

[typographie]

I have great temps and a lot of room to increase voltages and temps, so is there any possibility to get BCLK higher?

 

Most likely not. The problem is that a variety of the components on the Haswell platform tie their own clock frequencies from the BCLK. Overclocking via the BCLK is in effect overclocking those other components as well. Often the PCIe bus becomes unstable.

 

It actually sounds like you've got a great result, considering how little overclocking one can expect out of a locked Haswell chip. I'd probably call it a win and leave it at that.

[Valkyrie Lenneth]

dont use speedfan to monitor temps, use hwmonitor... and btw

 

dont overclock a xeon are u crazy haha

 

105bclk is like the absolute peak u wanna run... higher then that can harm it

[airdeano]

usually, i'd found that BLCK frequency also overdrives the PCIe bus. so any

devices under that protocol are affected greatly. usually GPU and/or RAM

and storage.

using STRAP method involves the multiplier (xeon is locked) and bus speed.

you'd increase the frequency, but lower the multiplier, or vise-versa.

[Curufinwe_wins]

Yea the instability is likely from everything other than the cpu. Ram, pcie bus etc (see what happens when you loosen ram speed/timings and then boot up)

Unfortunately the bus strap in haswell affects literally everything, which makes overclocking bus a little bit of a bitch.

(This was one of the reasons I was so excited when skylake gave full dynamic uncoupled bus clocks)

[JiriT]

Thanks for all of your answers.

1) Speedfan actualy works very well, I also have Intel Extreme Utility and RealTemp, and when I overclock I use all of them, but Speedfun tends to show higher temps (1-2 degrees), so that is why it is shown.

2) I am the type of a tinker who will never call anything win, but I got the point

3) I know that BCLK affects everything, but I lowered my multiplicator (can I call it so?) of RAM, so my RAM is at point where no problem can occur. I just dont know how it is with PCIe when I have nothing pluged into PCIe slot - GPU or other card.

Once again thanks for your answers, I heard that on linus tech tips forum is a great comunity which truly is. O post on two or three other forums and all I get were just insults that i am total idiot who buys xeon which is treetimes the price of 4770K and try to overclock it.

And once again, I have to say that xeons are the best. It is hi-performance beast, very comparable with 4770 (were released at the same time). Xeons are meant fo 24/7 heavy workload, have low TDP - 84W in my case (i messed up with undervolting as well and I was able to undervolt VCore in ofset -0,100V! which get me cca 70 W and I was able to achive temps about 42C). And i have no idea about prices in world, but in one small country in the midle of europe I get it cheaper then comparable i7. And could be overclocked a bit.
So guys, use xeons for every rig you make from now