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Should my cpu clocks lower with EXPO RAM enabled?

Slackjaw190

Slackjaw190

Slackjaw190

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I assumed enabling EXPO would increase system performance, but it seems to be having the opposite effect on my system.

Enabling EXPO has caused my CPU to operate at a slower speed of approximately 120 MHz (4850 MHz vs. 4970 MHz), leading to a 400 point decrease in Cinebench R23 scores. Is it expected to have lower CPU clocks running overclocked RAM?

CPU = Ryzen 7 7700
RAM = Corsair Vengeance 32GB EXPO (2X16GB) DDR5 PC5-48000C30 6000MHz Dual Channel
MB = MSI B650 GAMING PLUS WIFI.

CPU settings are standard, other than the -30 curve optimiser, but I've tried resetting to stock, and I still get lower clocks with EXPO enabled.
 
My uneducated guess would be that the increased power going to the I/O caps the total power budget, does it look like that's happening?

So far as I'm aware, Cinebench is not bothered about RAM speed, so faster memory doesn't give a higher/lower score.
 
Last edited:
Tetras said:
My uneducated guess would be that the increased power going to the I/O caps the total power budget, does it look like that's happening?

So far as I'm aware, Cinebench is not bothered about RAM speed, so faster memory doesn't give a higher/lower score.
Click to expand...
How do I check?
 
I guess it's power limited at 88W, so the CPU and RAM share power?

Power.jpg


I'll try upping the power limit slightly
 
Slackjaw190 said:
I guess it's power limited at 88W, so the CPU and RAM share power?
Click to expand...
Not the RAM. I'm suggesting it is the memory controller in the CPU.

When you enable EXPO, it increases the voltage and power draw of the I/O die and if you're hitting the limit it could be starving the cores of the extra power they need to boost higher. I can't recall the difference between EXPO on/off, but it can be around 8-15 watts, depending on the board and the overclock, which if my theory is correct could be enough to make the difference.
 
I think you're probably right, if I use 7700X TDP values the CPU clocks to roughly the same value if I have EXPO enabled or not.

I'm not going to notice the difference tbh, and I'll just go back to losing a few MHz with EXPO enabled and stock 7700 TDP values.

Thanks for your help
 
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Slackjaw190 said:
I think you're probably right, if I use 7700X TDP values the CPU clocks to roughly the same value if I have EXPO enabled or not.

I'm not going to notice the difference tbh, and I'll just go back to losing a few MHz with EXPO enabled and stock 7700 TDP values.
Click to expand...
Interesting. I'd agree though, should be more benefit from the faster RAM than the mildly higher clocks.

You could probably confirm the difference in consumption by subtracting the cores from the package. I thought that hwinfo showed the die separately, but apparently not :o
 
Slackjaw190 said:
Sorry that was HWMonitor not HWiNFO, HWiNFO does show more info, but I'm not sure what I'm looking for
Click to expand...
The total power being consumed is 141, with the cores being about 110 of that, so you've got 31 watts left over. It says the SoC consumption is 16.601.

With EXPO off, I'd expect the difference between those two numbers (total consumption and the cores) to shrink, so instead of 31 it'll be maybe... 15, 20?
 
Slackjaw190 said:
With EXPO disabled
Click to expand...
With EXPO disabled it cuts 8 from the SoC and 10-11 overall, so EXPO costs about 10 watts.

That's not much to make a big difference in score, but at 88 watt PPT, it goes from the cores having 77.5% of the CPU's power budget, to 66%.
 
Enabling EXPO sets high SoC voltage, increasing SoC power use which must fit in the total power budget. In your case from 1.015V to 1.3V
I suggest whether you increase power limit or not, SoC voltage should be lowered manually. I bet 1.2V works fine, probably could go even lower. 1.3V is ridiculous
 
Is this better, I went straight to 1.1v and seems stable - stock 7700 power settings. I guess dropping the SoC voltage frees up power for the cores to use?

Power-EXPO-1-1v.jpg
 
Slackjaw190 said:
Is this better, I went straight to 1.1v and seems stable - stock 7700 power settings. I guess dropping the SoC voltage frees up power for the cores to use?
Click to expand...
Looks like you've saved around 7-8 watts by lowering the voltage, which gives the cores a little bit more to play with.
 
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