Ryzen 5900x with DDR4 or 7800x3D with DDR5?

Hey there, I'm planning on building a pc soon and have settled on using a Radeon 9070xt as it looks like the best GPU for me as I wanna use Linux and dgaf about raytracing. Thing is, I'm split over what CPU to buy and if the extra 300/400 euro spent on RAM would be worth it. My brother has some DDR4 lying around and I'm not sure if the CPU + RAM upgrade would be worth the cost. My overall budget is 2 grand and I have a few parts (SSD and Power Supply)from an old pc that needs to be put out to pasture so I'll hopefully be able to save some money. I live in Ireland 🇮🇪

There's probably no right answer to this but some feedback would be appreciated :)

What are you using your computer for? What speed is the old DDR4?

14600 + 32g ddr4

What are you using your computer for? What speed is the old DDR4?

What is the PC for? 5900X is not worth spending extra on for gaming, but 7800X3D is made for it.

There is a right answer.

7800X3D without a doubt.

I would say with your budget I would go with the AM5 setup, those two aren't really anywhere close to each other for gaming performance.

I'm less worried about he CPU cost. I just feel uneasy spending so much on RAM when it was so cheap,

7800X3D /DDR5

If you're playing TF2 / CS2, save the money and go with AM4 and put in a x3D instead of the 5900x. The 5900x is a productivity CPU. If you main game, get get a 5500x3D off AliExpress or a 5800x3D.

For gaming, it should be between Ryzen 5800X3D vs 7800X3D as they are around at the same price. Here in Australia, I can get any of them for around $550 (AUD).

The 7800X3D is around 15% to 25% faster than the 5800X3D and offers an upgrade path via the accompanied AM5 motherboard.

However, since you are getting DDR4 RAM for free, there are big cost savings to be had compared to buying for DDR5 RAM.

Therefore, besides the RAM, the only major difference is the motherboard. An AM4 motherboard costs around $80; honestly, would you care that there's no upgrade path for that $80 part?

The big questions is whether that 15% to 25% performance increase is worth the extra cost from the DDR5 RAM?

thanks for the detailed reply, I'll think this over :D

I just wanted to note, feel free to use ray tracing with the 9070xt. It's not night and day compared to Nvidia anymore. It just loses maybe 3-8% more frames compared to the 5070ti depending on the game. It still punches well above the regular 5070 with ray tracing on. The newer path tracing, that's become an Nvidia-only thing for the moment.