Hey all. First off, apologies, this will be a long thread as i have many many thoughts
Its been 3yrs since iv posted here. I joined when i built my 3950x system, and, coming from an Intel back then, wanted to try and control the temps on the AMD as they were much warmer. Im back in the same boat now with my new 7950x build. I know its not news that these new chips run quite warm/hot, and ill admit i know very little about whats going on under the hood, and how to optimize things in BIOS, but iv been fiddling around with settings for a few days, watching videos, trying to get my head around things, and a couple points have me confused.
First off, build info for this workstation:
7950x
MSI Meg Ace x670e
64gb Fury 5200 (xmp not enabled currently)
Liquid Freeze 2 280 AIO / Noctua HT2 paste
1000w seasonic
MSI gaming 3060ti - display
Asus 3090 - rendering
The 1st thing i dont understand is the voltage on these new chips. When i run HWinfo, the stock settings dont drop the voltage below 1.39v at idle. On my previous 3950x system, the voltage would drop down to 0.8xx V at idle (and i was using a mild -0.1v (iirc) entered as an undervolt), and the system was stable. I was expecting things to operate similarly on this 7950x, but perhaps im wrong? Surely having the voltage constantly sitting at 1.3xx is leading to increased temperatures or power consumption? Or is that not how it works anymore?
After some youtubing, and trying to get my head around the new Eco Mode, settings that i could change and understand, i tried various configurations. Nothing will allow the voltage to drop as low as i was expecting/hoping. Again, maybe this is just me being misinformed... or wishful.
Across the board for my tests, my idling temperature never goes below 39C. I was expecting it more in the mid 30s, but again, perhaps not how things work with the 7950. This idle temp lower limit remains if i tried Eco mode, or setting a manual undervolt of up to (or down to?) -0.125v. I was expecting that lowering the voltage by that amount would surely have an effect on the idle temps... but it didnt. It idles at the same temp as stock. So again, confused.
Since this is a workstation, im using Cinebench R23 as my stability test. I had quite a few batches of settings that crashed while windows was loading, arriving at the desktop, or during my 1st attempt to write this post. As of this moment, things seem stable, but with undervolting, it seems the instability happens at lower loads, not higher loads. I was getting better CB23 results with undervolting than with Eco Mode. My admittedly uneducated guess is that Eco mode is doing nothing for the idle voltage, and only adjusting the power under load, not allowing it to go too crazy. So while everyone says Eco mode is great (at it def helps with load temps), it wasnt what i expected it would be. Here are some results...
Stock: 37200. PPT 208w. 95C.
PBO Eco Mode: 35500. PPT 140. 75C.
Undervolt (PBO -250mhz, -0.122V offset): 38000, PPT 180. 85C (PBO thermal limit)
(HWinfo never tells me im thermal throttling, but isnt that what the stock setting is, and my last setting there for 85C? isnt that a thermal throttle?)
That final undervolt setting is where im at currently. My understanding of the PPT #s i was getting is that this is the max power consumed during the tests? My current PPT in HWinfo is around 27w. So, im guessing this is the idle power consumption?
Either way, as for the CB23 results above, the last wasnt my best score, but since the best score ultimately crashed as i was trying to write this, i discarded those results (38170). My initial testing was done by setting the cores to fixed values, as i think is the standard way things are done? But when i found you could shave off mHz in PBO, that seemed like a better way to do it as im guessing it still allows the system to boost each core to whatever it can achieve (rather than giving each core a fixed value), and I can just back that off a little to play a bit more safely with the undervolt. So thats my thinking there. No idea if its correct. HWinfo currently tells me my core clocks are around 5.5ghz, with a min of 4.8. I recall when i tested by setting all core to 5ghz, that it stayed there and never changed, and i guess thats the point. So perhaps by doing it the PBO way with negative mHz, its allowing for the system to be more adaptable and more efficient? I have no idea.
So for these current settings, HWinfo was telling me that, during the render, the core clocks went from 5.5gh, down to closer to 5 even. Similarly with the voltage, its idling at 1.3v, but then during the render test, it drops down to about 1.09v. Just curious why this is? Why is it telling me my idle speed and voltage is higher than when the actual work is being done?
I briefly tried the curve optimizer as the ONLY adjustment i was running, but i didnt have much luck and couldnt even get into windows. I just did this following the suggestions of a youtube video, which said PBO limits should be off when using the curve. I dont know if thats true or not? He was using the older 59xx chip. Either way, I was most likely using too high of a setting (started at 20, worked my way down to 10, but still no luck), so i may revisit that idea later.
So while there are a handful of questions throughout here, the main question is why am i stuck idling at 1.3v? Does anything iv said above make sense? Am i making reasonable adjustments or am I way off?
The final point, and somewhat of an aside to the above, is on my 280 cooler. Is my 40C temp lower limit due to this? When researching build components, i decided on the 280 vs the 360 because id seen a test that they were fairly similar in cooling ability. The 280 has a higher air flow, but less surface area, whereas the 360 is the opposite. Since the 280 is smaller overall and would allow me another fan up at the top of the case, i opted for that. Im not sure how much (if any) improvement i would see with a 360. All the above testing was done with the CPU fan on stock settings. It wouldnt realy ramp up much during my tests reaching 85c. But just now for kicks, i turned it up to 100% speed, idle temps remain at 39/40, and my CB23 score and temp remained the same. Interesting though that nothing changed from full speed to like 50% speed. So perhaps if 40C is the lower limit of this cooler, the 360 might be a bit better since it has more surface area, as it seems the airflow isnt realy changing anything.
Also, FWIW, perhaps iv been stingy on the thermal paste as well? I realy didnt want any leaking out and getting underneath the IHS, so i probably purposely tried to keep it on the lighter side. Temps had initially been higher, but it lead me to suspect something, so i removed the cooler and found that the paste had somehow only covered 1 side of the CPU, with very little on the other side. After reapplying, its better now at my current 40c. Im also unsure about overall screw tension when tightening down the cooler, but i thought it was better to err on the side of caution, and only tightened it until the screwdriver started to give me moderate resistance. Definitely tighter than finger tight though.
Apologies for the long thread. I just like to be as detailed as possible and try and include as much info as possible. Any and all insights are welcome. Thanks!
