Should I disable the second CCD on my 7900X?

[Vya Domus]

that's why disabling either CCD restores most of it.

Do you know that for a fact or are you just speculating, I can't find any benchmarks about this.

Edit : I found this : https://www.techspot.com/review/2821-amd-ryzen-7800x3d-7900x3d-7950x3d/

Turns out most of the time a 7900X3D with one CCD is slower, go figure.

 

[Dr. Dro]

Do you know that for a fact or are you just speculating, I can't find any benchmarks about this.

The 8+8 chips are traditionally faster at games than the 6+6, and the 7900X3D trails every single benchmark when compared to the 7800X3D, which is a contiguous 8 cores without a resource imbalance issue

I searched some of TPU's newer reviews but W1zz either dropped the 7900X3D or never included it in his charts to begin with, so... here's just a few

The 7600X3D is a "bit" slower, yes, but also lower power limit and generally better minimums. The 7800X3D which has all of its resources easily utilized due to optimal topology is vastly superior and in many cases, delivers even better performance than the 8+83D 7950X3D in some games

 

[Vya Domus]

and generally better minimums.

That's not true in the benchmarks I found, it's not just slower but has worse minimums as well most of the time, if you can find any that shows otherwise by all means but I think it's safe to say turning off 1 CCD categorically isn't a good idea in most cases.

The point is do you understand that this isn't unique ? There are games where a 7950X is faster with 1 CCD, no V cache involved, no asymmetric architecture. This behavior is not unique to the 7900X3D.

 

[Chrispy_]

That's not true in the benchmarks I found, it's not just slower but has worse minimums as well most of the time, if you can find any that shows otherwise by all means but I think it's safe to say turning off 1 CCD categorically isn't a good idea in most cases.

This line of reasoning is purely a result of the clockspeed and TDP differences between a 7950X3D and 7800X3D. Clock them the same and give them the same TDP and they should tie at best, and the 7800X3D should be faster if game threads are scheduled on the wrong cores by the OS.

 

[Dr. Dro]

That's not true in the benchmarks I found, it's not just slower but has worse minimums as well most of the time, if you can find any that shows otherwise by all means but I think it's safe to say turning off 1 CCD categorically isn't a good idea in most cases.

That'd be because 6 cores are generally no longer enough to get the best out of a high-end GPU such as the RTX 4090. It'll be a slightly different story with a weaker card, I reckon. But I concur there is little reason to go out of your way to cripple your CPU, particularly since there is already a driver to compartmentalize workloads between the 3D and non 3D parts of the CPU

 

[Vya Domus]

That'd be because 6 cores are generally no longer enough to get the best out of a high-end GPU

Then how are you so convinced this must be because of the topology when in reality you wouldn't be able to distinguish why it happens because of this, like I said there are cases where even a 7950X performs better with one CCD, this is not special.

 

[Dr. Dro]

Then how are you so convinced this must be because of the topology when in reality you wouldn't be able to distinguish why it happens because of this, like I said there are cases where even a 7950X performs better with one CCD, this is not special.

It's the magnitude it occurs. The 7800X3D is so much faster that it feels like it's several generations ahead.

 

[Vya Domus]

The 7800X3D is so much faster that it feels like it's several generations ahead.

Dude, you realize the 7900X3D is still the 3rd fastest 7000 series CPU in gaming, those are the facts, not what it feels like.

 

[A Computer Guy]

I have a 7900X with two CCDs that have 6 cores each. Should I disable the second CCD and just use 6 cores? This is for gaming performance only.

Or should I keep both CCDs on and use the 12 cores and cross CCD latency?

I have the option in my bios to do this. Just came out.

No unless you know you have a game that is specifically effected by this. I would rather use modest PBO and Curve Optimizer settings to bring 2nd CCD to performance parity with the first CCD. This way if your game bounces arounds cores it will minimize any performance penalties bouncing between CCD's with different frequency or at least help ensure more consistent frame times.

 

[Dr. Dro]

Dude, you realize the 7900X3D is still the 3rd fastest 7000 series CPU in gaming, those are the facts, not what it feels like.

"Third fastest" and "second slowest" in a ranking of four, or decidedly the slowest if you exclude the 7600X3D which has limited global availability... the glass half-empty and half-full conundrum. Unless you're factoring in the non-3D chips into the mix, but those lose out anyway

 

[Vya Domus]

"Third fastest" and "second slowest" in a ranking of four, or decidedly the slowest if you exclude the 7600X3D which has limited global availability... the glass half-empty and half-full conundrum

Yeah but you're talking about it as if it's utter crap or something when in reality it's still literally one of the fastest gaming CPUs you can buy, it's even faster than the newly released 285K lol. And that's as is, out of the box, no need to disabled CCDs or anything.

 

[A Computer Guy]

Yeah but you're talking about it as if it's utter crap or something when in reality it's still literally one of the fastest gaming CPUs you can buy, it's even faster than the newly released 285K lol. And that's as is, out of the box, no need to disabled CCDs or anything.

On the flipside people are still gaming with R5 2600! 7900X3D at it's best price point defiantly not garbage and some people who do mixed gaming and productivity saved a lot of money for GPU by going this route. There are no bad CPU's just bad prices. (except for those unpatched CPU's that slowly commit hari-kari for the top FPS and power consumption numbers)

 

[Dr. Dro]

Yeah but you're talking about it as if it's utter crap or something when in reality it's still literally one of the fastest gaming CPUs you can buy, it's even faster than the newly released 285K lol. And that's as is, out of the box, no need to disabled CCDs or anything.

All I'm saying is that it's not a particularly praiseworthy product, the chip to end all chips. The 285K is... just bad lol. Will be interesting to see how Intel manages the situation - will prices drop, will they rush the successor out, will they endure and make an unusually good chip the next gen - my money's probably on #2 here

There are no bad CPU's just bad prices

This is my motto as well

 

[Onasi]

There are no bad CPU's just bad prices.

*cough* Bulldozer *cough*

Going back on topic, I also agree that there is no reason to turn of a CCD on a 7900X. It’s a fine CPU as is and perfectly performant in gaming. I think that the outliers that are X3D chips paired with testing at low resolution with halo cards has somewhat warped the perception of people on what “good gaming CPU” is. You are likely to be GPU bound anyway in most scenarios. Unless one really needs his 800 frames in CS or something.

 

[A Computer Guy]

*cough* Bulldozer *cough*

Oof I forgot about that one. We don't talk about that one here.

 

[Solaris17]

I'm just going to keep the 12 cores enabled. Thanks. I don't care about an extra 5fps if that.

I'm good. Carry on.

Jesus thank god.