Cinebench Open GL score drops dramatically when Speedstep is disabled

Hi there. It's me again. I'm still new to the X99 platform and I still have to learn a lot about overclocking on it.
But there is a really weird issue that I can't really get my head around.

So, I'm running my 5930K @ 4.5 GHz, so far so good. My Cinebench R15 OpenGL scores with my XFX R9 R290X DD 8GB Edition are around 125-132 fps. Now, when I go into the Bios and switch from Dynamic mode to Fixed mode which disables Intel's SpeedStep Technology and sets the CPU multiplier to a fixed value, my OpenGL results drop by about 50 fps!!!!!!
Does anyone know why??

Here are the results with and without EIST enabled

No other benchmark or the gaming performance seems to be affected by this.

hmm weird, did you allready tried 3d fire strike, and unigen Valley and heaven?

Did you do any overclocking to the ram?

Yes I did. Firestrike is around 12.000, Heaven 1780, Valley 2830. I think the scores are all ok for a single-GPU system.
The RAM is HyperX Predator 2800 running on the XMP 2 Profile at 2666 Mhz CL14-14-14.

hmm it might be something related to the ram "overclock"

Did you allready tried to give System Agent voltage a realy slight bump?

Well, I gave it a little offset voltage, but only like 5mV.
I mean, the weird part is that the system is perfectly stable. I stressed it with OCCT and it doesn't fail.

yeah it could of course also be just Cinebench.
If all the other benchmark tests dont show any weird frame drops, then you might not worry too much.

Still its weird somehow.

And that bugs me. I'd like to figure out what's causing this.
Can't find anything about it on the web. I mean, having EIST enabled isn't all that bad on an overclocked system like that since when the CPU is not stressed it clocks down to 1.2Ghz and the CPU sits nice and cool in the low 30s. Saves a lot of power as well.
I have a 4930K arriving at the end of the week and I'll put these two up against each other and see what happens.

well yes, you basicly should say a cpu throttle.
But then other stress testing should also suffer from the same issue.

What happens if you set the multiplier a bit back to lets say 42?
Just to check if its according to the overclock.

I'll try that when I'm in the office tomorrow.
I also used the Intel Extreme tuning utility for stress testing and it says "0% throttling"

okay will wait for that result.

I'll try at a lower clock speed and with some more voltage for the system agent.
Thank's for the help.

or you could try to sett back your ram to 2400mhz.
some motherboards seem to need a slight bump in SA voltage, if you wanne run memory higher then 2400mhz, i've readed about that somewhere.

If i remember it correctly, this was according to an Asus board.

The motherboard is an MSI X99S SLI Krait Edition

Allright, here we go. I tried out all the different scenarios we talked about. First, I couldn't solve the problem.
Giving the SA a little more voltage and setting the Memory Voltage to 1.36V increased the performance though. But still only when EIST is enabled. Clocking the CPU down to 4.2Ghz didn't change anything, manually setting the memory speed to 2400Mhz didn't do anything either. Whenever I set the clockspeed to a fixed value I loose between 50-60 fps in Cinebench OpenGL benchmark. When I disable EIST though, it gives me almost 300 points more in Cinebench CPU benchmark.
This kinda sucks. I don't get it.

Hmm yeah thats kinda weird.
Do you have the newest bios?

Yep, newest bios.
I reenabled both EIST and Turbo boost now and that gave me my 300p in the CPU bench back.
I still would like to find out what's causing the fps drop, but otherwise I'm kinda happy now.

Here are the results:

The numbers look good to me, still weird those fps drops.
i can only think about something related to the motherboard somehow, but yeah.... what could it be..

Right now the only thing that matters is being able to play GTA V on high setting in 3440x1440 anyways ;-)
I'll deal with the rest later.

allrighty.

yeah if you can play those games without any issues, and your other benchmarks show good numbers, then maybe just not botter too much with Cinebench

Just a thought, have you used MSI Afterburner or similar to monitor GPU usage and frequency when running the tests? I've noticed with my R9 290 that sometimes it does not clock to its maximum frequency, this seems to happen only under OpenGL but it's always fine with benchmarking software like unigine valley.

I'd be interested to know if yours does something like that only when your CPU settings are changed.