Best CPU platform and memory for high-ram gaming & productivity machine?

[FeijoaBoa]

Budget (including currency): I have more money than sense

Country: Australia

Games, programs or workloads that it will be used for: Gaming, VR, but also machine learning stuff and development

 

So I want to make a new build PC that's decent for both gaming and productivity. I'm a software developer and after work I like to train small ML models on my local machine, also I am an irredeemable tab-hoarder and I often like to keep all my dev environments open in different virtual desktops so I don't lose context. Gaming I pretty much want it all, and I play VR too.

 

My last build in 2019 I had the same objectives, and I screwed it up by going threadripper. I got a 2990WX and the low single-core speeds and the bad handling of multiple numa nodes meant that it always was missing gaming potential and I had to faff with rebooting to disable/enable CCDs.

 

This time I'm planning "The 5 PC"; DDR 5, PCI-E 5, Nvidia 5000-series. I've got a (preorder, sigh) for a 5090, and now I need to consider the rest of the build. My main thing I'm not confident on is about ram speeds vs quantity. I know that if I go 4 sticks (or even 2 sticks but they're high capacity?) I will lose MT/s, but ideally I want more than 64GB. Are AM5 and LGA1851 similar, or does Intel handle more RAM better for higher speeds? I seem to see sticks with XMP profiles that are higher speeds than EXPO sticks.

 

I already know that a combo workstation/gaming PC can never be the absolute best at either - eg if I go 9950X3D instead of 9800X3D then I may lose some FPS due to multi CCD (hopefully scheduler is better than my Threadripper), and if I go 9950X3D instead of 9950X then I lose some clock speeds/workstation performance maybe. The same is true of RAM, if I go 2x16GB sticks for pure gaming I could even get to 8000MT/s on some platforms, whereas larger sticks seem slower and 4 sticks seems really slow. So I'm fine for a few percent loss either way, if I can get the 95% awesome gaming and 95% awesome productivity machine.

 

TLDR:

• Want best as possible of both worlds gaming and productivity
• Can't decide CPU platform and memory configuration - want 96GB+ of as-fast-as-possible RAM
• https://au.pcpartpicker.com/list/GD4FKq maybe? (Not able to select 9950X3D yet in PCPartPicker)

 

[CatTNT]

As far as I know, Intel recently handles RAM at far higher speeds than AMD does. In my experience, the exact same kit of 2x32 CL 30 DDR5-6000 EXPO RAM on a 7700X and a 14900K deliver drastically different performance. On the 7700X, this kit game me around 60 GB/s of read/ 30GB/s write with 84 ns latency, and right now on my 14900K it gives me 92GB/s read and 86GB/s write., with a 74ns latency, with modified timings. "Stock" EXPO settings on this kit gives 82GB/s write, all other speeds are the same. 

This is assuming you NEED such high and fast RAM speeds. Intel's 285K, with a special CUDIMM motherboard can support 10-12000MT/s RAM, but I don't think that could ever compensate for the shit core architecture, you'll still be faster with 9800X3D and DDR5-6000 in almost every scenario. You need to determine how much RAM bandwidth your applications really need, and add a  speed buffer on top just to be sure, that would be my guess. 

If you do determine that you need 90-100GB/s of RAM bandwidth, then Intel is your only option, at least a 14900K, or maybe even a 265K/285K. But i seriously doubt that would happen.

For gaming, especially at 4K, RAM becomes far less important than the GPU, and CPU. 

RAM speeds with AM5:
https://www.techpowerup.com/review/ddr5-memory-performance-scaling-with-amd-zen-5/21.html

Intel 285K tested with CUDIMM:
https://www.techpowerup.com/review/intel-core-ultra-9-285k/27.html

It looks you have hard decisions to make if you seriously care a lot about both RAM bandwidth and gaming performance. Despite the CUDIMMs having more bandwidth, their CL rating suggests that their increased latency would make them worse for gaming. Given the fact that even the 285K struggles against AMD's 7000 series sometimes, this doesn't look good. 

My advice, unless you truly, really determine that you need so much RAM bandwidth, is to just get a 9950X (or 9950X3D when it comes out), and ensure you have enough RAM, and ensure it's DDR5-6000 with the lowest CL possible (Cl28 or CL30)

[FeijoaBoa]

Thank you so much for your reply CatTNT! Maybe the midwit meme is right

 

 

Is there any danger with going for sticks that only have XMP and not EXPO? It's slim pickings here in Oz sometimes

[brob]

2 hours ago, FeijoaBoa said:

• Want best as possible of both worlds gaming and productivity
• Can't decide CPU platform and memory configuration - want 96GB+ of as-fast-as-possible RAM
• https://au.pcpartpicker.com/list/GD4FKq maybe? (Not able to select 9950X3D yet in PCPartPicker)

 

The 9950X3D is likely the best choice for use case. Au.pcpartpicker.com does list the 9950X3D when it is compatible with other components in the build. You can turn off this feature when selecting a component, uncheck Compatibility Filter. I expect the CPU will appear in your build options once Gigabyte adds the 9950X3D to the motherboard CPU support list.

 

Personally, I would keep memory simple and get 2x48GB DDR5-6000 CL28. (G.Skill has some Trident Z5 NEO kits that they qualify for the motherboard.) 

 

https://www.techpowerup.com/review/ddr5-memory-performance-scaling-with-amd-zen-5/ offers some insights into performance at different memory speeds.

[igormp]

On 2/6/2025 at 8:23 PM, FeijoaBoa said:

This time I'm planning "The 5 PC"; DDR 5, PCI-E 5, Nvidia 5000-series. I've got a (preorder, sigh) for a 5090, and now I need to consider the rest of the build. My main thing I'm not confident on is about ram speeds vs quantity. I know that if I go 4 sticks (or even 2 sticks but they're high capacity?) I will lose MT/s, but ideally I want more than 64GB. Are AM5 and LGA1851 similar, or does Intel handle more RAM better for higher speeds? I seem to see sticks with XMP profiles that are higher speeds than EXPO sticks.

2x48GB should do fine in both platforms.

If you need more than 96GB, then you start to face some issues. You can wait for the availability of some 64GB CUDIMM sticks and shove 2 or 4 of those into an intel platform, and it should work fine. Level1 has a video on it:

I'm personally planning on buying 4x64GB CUDIMM sticks to use with a 9950x, but I'm ok if the frequency ends up being slow.

 

On 2/6/2025 at 9:44 PM, CatTNT said:

As far as I know, Intel recently handles RAM at far higher speeds than AMD does. In my experience, the exact same kit of 2x32 CL 30 DDR5-6000 EXPO RAM on a 7700X and a 14900K deliver drastically different performance. On the 7700X, this kit game me around 60 GB/s of read/ 30GB/s write with 84 ns latency, and right now on my 14900K it gives me 92GB/s read and 86GB/s write., with a 74ns latency, with modified timings. "Stock" EXPO settings on this kit gives 82GB/s write, all other speeds are the same. 

The 7700x is a single CCD part, the dual-CCD parts can achieve better bandwidth due to the extra ports on the IOD.

 

[FeijoaBoa]

okay thanks folks, these are all very helpful replies. What I'll do is be patient for the 9950X3D (it'll take that long for my 5090 to ship...) and get the fastest 2x48GB kits I can (where fast = at least 6000MT/s and then either as low latency or as high frequency as I can get, realistically the former for 48GB sticks)

[Somerandomtechyboi]

On 2/7/2025 at 9:44 AM, CatTNT said:

CL rating

Literally among the most useless timings 

Alongside the other primaries with an exception to trcd as that does seem to have a performance impact

 

Reason to get low cl is because the low cl bins have better ics, anything c34 and lower is usually hynix a die and thats pretty much the best ddr5 ic you can get

 

and yes you can get the exact same thing on 5600c46 hynix green pcbs (hmcg78agbua081n) and theyll clock the same for the most part so if available at a decent price thats a good way to save money albeit no xmp but thats kinda useless anyways when this exists

And obliterates even those 6000c26 bins at stock xmp though thats a pretty high bin so you should see a difference between them and regular 6000c28 and up unbinned hynix a dies in terms of overclocking (ex being able to do 6400c26/24 or 8000c30 with lower volts)

And yes cl has basically been relegated to just a binning tool cause thats about all its useful for these days but i still chase low cl anyways just for the fun of it since i tend to be very voltage happy

 

Frequency = higher bandwidth but also lower latency so its prefferable to push this as high as possible though with ryzen cause of imc limit its usually not worth it till you can hit 8000 and even then thats pretty difficult if you dont have a b650m hdv or any other 2dimmer with minimal perf gain due to the latency penalty from going 1/2 uclk which is only just overcome at 8000+ albiet secondary benifit of being able to run really low vsoc for lower power draw

Though drawbacks being the need for a ram fan alongside being a pain to tune hence why i dont bother reccomending 8000+ unless were talking apus that have basically no latency penalty for 1/2 uclk and you can push 9000+ given a good chip (albiet again only 2dimmers can clock 8400+ reliably cheapest of which is the b650m hdv)

 

If 6000c26 is available and money is no object then go for it though itll be pretty useless in stock form so only go for it if you overclock, otherwise just get any 6000 bin thats c34 or lower

 

On 2/7/2025 at 8:23 AM, FeijoaBoa said:

machine learning stuff and development

As for productivity this will be more of a gaming focused machine then cause machine learning needs alotta vram which means multiple gpus which means consumer platform is woefully inadequate due to lack of pcie lanes

 

If you just need gpu power or a ton of multicore then go sp3 with epyc as 16c32t 7282 go for peanuts if gpu only with 64c128t 7c13 going for 700$ if you need the multicore, ram is also dirt cheap so you can get 256/512 relatively cheaply (96gb ddr5 > 256gb ecc ddr4 pricewise) though boards are kinda expensive just that they swing alot in price so sometimes theyre closer to 400$ other times theyre closer to 700$

 

You wont be compromizing gaming thats for sure but productivity will almost always be compromized on these kinds of systems unless its not the type that can leverage hundreds of cores hundreds of gb of ram nor more than 3 gpus in that case a regular system would work just fine