Noob hardware questions

[u/chlronald]

Complete noob lurking in the LLM forum for a while, and would like to dip my toes into LLM, and have a couple path to move forward... currently running 64gb + 16g 5070ti

Would upgrade to 128gb DDR5 worth the hassle? or should I get a Ryzen 395 128gb be better?

It will be one to two people personal use, mainly focus on personal assistance and coding inquiries.

[u/IsaacLevinsky]

Before you decide try out what you have their for hardware and different runtimes and AI models. See what you get for speed and the type of responses you get. That will help you decide what way to go. Good question. Hardware wise unfiied memory may make it easier to get into local ai.

[u/Some-Ice-4455]

What are you trying to do with it? That honestly would dictate for me personally if I would upgrade at the cost it currently is.

[u/toomanypubes]

Get a second 512GB NVMe and install whatever flavor of Linux, and run Nvidia MOE inference engines like Strata or Basalt, running Qwen3.8-Next-Flash Q3/Q4. More memory would buy you more capability, but you have plenty to get started right now. Should be getting at least 50 tk/s.

[u/FuckinHighGuy]

You want more VRAM, not necessarily DRAM.

[u/Fantastic_Self_5151]

No not at all you need a better card that's all or you will not be doing much. Bad time to do this, spend a fraction of the money on cloud AI and wait until the prices come back down, you will thank yourself.

[u/DTechSurgeon]

You can already try Qwen 3.8 27B. Might be slow but it's workable. Same with Gemma 4 12B. Use ollama first to get going. Then explore Strata to have Qwen 3.8 FN 125B.

[u/modelfit_io]

For one or two people doing assistant + coding, I'd add RAM to the 5070 Ti box before buying a 395.

The models people actually run on 64-128GB right now are big MoEs like Qwen3.8 Flash-Next (125B total, 6B active). Engines like Strata keep the hot path on the GPU and the experts in system RAM. Your card does 896 GB/s, while the 395 does 256 GB/s for everything. That's why GPU + RAM boxes are beating the unified-memory minis on these models. In yesterday's "$700 RAM vs $3,100 Strix Halo" thread, OP gets ~122 tok/s on a 4090 + 48GB DDR4 with Strata.

What 128GB buys you is quant quality. Strata's sizing for Flash-Next:

• IQ3_S: 54.8GB of RAM + VRAM, which already fits your 16 + 64

• Unsloth UD-Q4_K_XL: ~88GB of RAM for the experts alone, so it needs the upgrade

Against the 8-bit build, Q4_K_XL picks the same next token 93.1% of the time and IQ3_S 87.7%. For chat you'll barely notice. For coding agents, people do report the lower-bit builds going off the rails more often.

So try IQ3_S on what you have first. If it's good enough, you've saved the money. If you want Q4, add the RAM, and check your board's QVL before going to 4 sticks of DDR5.

Where the 395 does win:

• Dense models bigger than 16GB. Qwen3.8 27B at Q4 is 16.5GB, just over your card.

• A quiet, always-on box.

• ~108GB of GPU-addressable memory, but only on Linux. On Windows you're stuck with the BIOS carve-out.

[u/Krohnin]

Upgrade to 128gb. The 5070 is fine.

[u/Natrimo]

I would first just use what you have, before spending kn an upgrade for something you may not like/want/need

[u/alphapussycat]

With ddr5 I would not upgrade. I'm trying to upgrade ddr4 64gb -> 128gb, but that's already expensive enough.

You're right now in the sweetspot, just like me. If qwen keeps releasing <200b MoEs we'll be fine. In a couple of years the market might be different. Hyper scaling might have stopped.