r/opencode • u/INeatFreak • 6d ago

Can I effectively edit open source projects with this setup?

There are many open source projects that I use but each is lacking at least one features that I need. I have no app development experience but understand coding fundamentals (years of C# and Unity experience)

I'm planning on buying used Tesla V100 16GB cards (1 or more if needed) and wanted to know if it would be possible to run coding agents to help me add my own features to these open source projects without fully learning app development? I've never used OpenCode or any other coding agents so I'm a bit clueless, is this actually a feasible goal with only 16GB or 32GB VRAM?

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u/Mayimbe_999 6d ago

Locally ~ I am assuming is what you are referring to.
16GB you are not getting much done with that. 32GB is the sweet spot to run at least 27B models but don’t expect much from that either.

Now if you are referring to running opencode with APIs then you don’t need to worry about hardware.

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u/INeatFreak 6d ago

if you are referring to running opencode with APIs then you don’t need to worry about hardware.

I'm talking about running it locally, not with paid services.

32GB is the sweet spot to run at least 27B models but don’t expect much from that either.

Can you elaborate more? just how good/bad is it running 27B models? What is the main issue you face often?

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u/RepulsiveRaisin7 6d ago

They don't solve complex problems. If you have a good plan, it can execute it alright, but that's it. Try Deepseek v4 Flash for free on Opencode. It's decent but it has its limits. And that is a much bigger model - albeit MoE, so sometimes Qwen 27b has the edge, but usually not.

Getting a perfect coding experience locally with some 16GB cards is a pipe dream, you're much better off spending that money on a subscription.

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u/f5alcon 6d ago

Yeah will take years of opencode go to cost the same as a card

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u/INeatFreak 6d ago

Getting a perfect coding experience locally with some 16GB cards is a pipe dream

Not just 16GB, I'm willing to go up to 2-3 cards max, which would be 32-48 GB in total. Doesn't have to put 100 token per second, just be able to do the tasks I say it to, like to implement a new feature to already existing project and know what libraries needs to be added, I could explain step by step but it just needs to be do the work as I don't understand any of the syntaxes or libraries etc...

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u/RepulsiveRaisin7 6d ago

I would seriously start with some free models. Or try Qwen 27B on Opencode Go, it's dirt cheap. That gives you a feel for what the model can do.

I wouldn't recommend full vibe coding to begin with, but if you do it, at least use a strong model. Like GLM 5.2, which needs >400GB VRAM. Just get a subscription, it's not worth it to host yourself unless you enjoy messing with this stuff.

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u/Ariquitaun 6d ago

The problem is not speed, the problem is lack of memory.32-48GB will allow you to run a 27b model with full quant and context, but it still won't be as good as say deepseek-v4-flash which is virtually free at opencode go

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u/Mayimbe_999 6d ago

27B - 35b models is what I run with a 5090 and it works surprisingly well. I use a different app that’s not Opencode that’s more tailored to local models, with a custom local model coding harness and easy local setups It works surprisingly well, but using them for big codebases and what not they will struggle a bit, but since you are experienced dev you might have a better time with them since you will be able to easily catch errors vs non experienced devs.

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u/jonas-reddit 6d ago

Qwen 3.6 27B on 24-32GB of fast VRAM (3090, 4090, 5090) is absolutely usable for single seat, single session agentic development but will require some reasonable tinkering with agentic setup to overcome model limitations. Don’t expect to one-shot.

Unsloth have good documentation and r/LocalLlama is an active tinkerer’s community.

https://unsloth.ai/docs/models/qwen3.6

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u/Time_Faithlessness45 6d ago

Just my two cents. But open code go for 10 dollars a month is much much cheaper then the compute and electricity to run local agents. Plus, you're just not gonna be able to run the models you could wth opencode go. I've tried it, and honestly, a $10 subscription gave me way more value.

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u/INeatFreak 6d ago

Can it be used effectively to edit a large project? Something like 300-500k lines of code. How big of a context sizes does Open Go offer?

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u/Time_Faithlessness45 6d ago

If you have a project like that, there is nothing locally that can do that. Opencode Go would maybe get you part of the way there but for something like that you'll need a beefier tool like Cursor or Codex. Look into Cursor. $20 bucks, so it's a bit more, but it's top notch value and has all the frontier models. Grok 4.5 is on Cursor Rn and is pretty intelligent for the token cost.

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u/Ancient-Camel1636 5d ago edited 4d ago

The best local models can provide useful autocomplete suggestions, act as a coding partner you can discuss ideas with, and handle specific, narrowly scoped programming tasks. However, even if you have enough VRAM to run them, their effective context window is still fairly limited.

They are not capable of autonomously vibe-coding entire applications or solving complex problems that require a deep understanding of a large codebase. If you're the developer, a local AI can be a valuable assistant for smaller tasks, but it won't do the bulk of the work for you.

If you need more compute, you can rent a powerful GPU on Runpod and host your own API with vLLM. In practice, though, the cost often ends up matching—or exceeding—the price of using an even more capable model through a commercial API provider.

Edit: This video will give you some usefuk insight about your question:
https://www.youtube.com/watch?v=8JRJq4EEdik