this post was submitted on 22 Dec 2023
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Now Ryzen 7900X is cheaper than 7900 what is weird. Is it possible to run 7900X undervolted to reach the low power consumption of Ryzen 7900? If yes, is it better to buy this cheaper 7900X or 7900 which has 65W TDP?

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[–] [email protected] 10 points 10 months ago* (last edited 10 months ago) (1 children)

Yes get the x variant, its easy to limit, if you dont need the extra cores get the 7800x3d

[–] [email protected] 2 points 10 months ago (1 children)

i need my pc for photo editing, so i think 7900 or 7900x should be better than 3xd.

[–] [email protected] 2 points 10 months ago

Anything that benefits from extra L3 cache will benefit from the x3D. I dunno if photo editing is one such tho, probably not.

[–] [email protected] 5 points 10 months ago (1 children)

You won't be changing the voltage on the CPU, but there's built in settings to limit the TDP down to whatever you want. If efficiency is also your goal you also want to limit the maximum clock speed (also in the same software).

https://support.punchtechnology.co.uk/hc/en-us/articles/6438162546461-How-to-set-a-TDP-PPT-Power-Limit-on-AMD-Ryzen-CPU-Processors

[–] [email protected] 1 points 10 months ago (1 children)

do i need the mainboard with the "highest" chipset or the with the cheaper chipset it will be possible too?

[–] [email protected] 2 points 10 months ago

In theory the A series chipset will run a 7950x3d or whatever the highest end CPU is. It's the power delivery of the board that matters more. Since you plan on underclocking it then in literally any board should work just fine with it.

I wouldn't cheap out that much on a board. Get a reasonable B series board, not some A series or bottom of the barrel B series if you're pairing it with such a high end CPU.

[–] [email protected] 2 points 10 months ago

You cna use eco mode in UEFI BIOS to limit the power draw. It's easier and morenreliable than the software (ryzen master) method.

[–] [email protected] 2 points 10 months ago (1 children)

Why any of those instead of the 7800x3d?

[–] [email protected] 1 points 10 months ago (1 children)

why should i take this 78003xd? it takes more power and is slower tgan 7900x.

[–] [email protected] 1 points 10 months ago* (last edited 10 months ago) (1 children)

It's better for games, better performance. The cache makes a big difference. And has better cache/core distribution than the 7950x3d and 7900x3d, so it has consistently better performance for games.

The 7900 is only better for tasks that can take advantage of the extra cores, which are basically 0 for normal users.

[–] [email protected] 2 points 10 months ago

spoken like a true gamer

[–] [email protected] 1 points 10 months ago

Thank you all for your help.