# Lightmatter CPUs and Stan

**URL:** <https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820>\
**Category:** General\
**Created:** [August 5, 2021, 4:05pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820 "2021-08-05T16:05:03Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![bparbhu](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/bparbhu/32/2722_2.png) [@bparbhu](https://discourse.mc-stan.org/u/bparbhu)\
**Post date:** [August 5, 2021, 4:05pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820/1 "2021-08-05T16:05:04Z")

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Something I was curious about is whether anyone has used a Lightmatter CPU with Stan.

Here’s a link to their page.

> **[Lightmatter](https://lightmatter.co/)**
>
> The photonic (super)computer company.

They specialize in building computers around Light-based processors that are supposed to rival NVidia performance by close to 10 fold.

I was curious as to what performance is like on those CPUs vs traditional x-86-based CPUs or even Nvidia/AMD GPUs.

I realize this is very niche but it does seem like an interesting CPU architecture for computationally intensive workloads.

Just curious to see if anyone has used these and if so what was performance like.

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**Author:** ![mike-lawrence](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/mike-lawrence/32/59_2.png) [@mike-lawrence](https://discourse.mc-stan.org/u/mike-lawrence)\
**Post date:** [August 5, 2021, 4:55pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820/2 "2021-08-05T16:55:03Z")

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They are not in the wild yet. [This interview](https://youtu.be/t1R7ElXEyag) suggests they won’t be available until the end of the year.

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**Author:** ![mike-lawrence](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/mike-lawrence/32/59_2.png) [@mike-lawrence](https://discourse.mc-stan.org/u/mike-lawrence)\
**Post date:** [August 5, 2021, 4:57pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820/3 "2021-08-05T16:57:59Z")

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Also, it specifically can do only linear algebra (possibly matrix-vector multiply only?), not general-purpose computing.

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**Author:** ![bparbhu](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/bparbhu/32/2722_2.png) [@bparbhu](https://discourse.mc-stan.org/u/bparbhu)\
**Post date:** [August 5, 2021, 5:10pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820/4 "2021-08-05T17:10:24Z")

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Cool, thanks for letting me know @mike-lawrence , I appreciate it. Just found out about this last week, so I’ve been curious as to what these kinds of machines are capable of and when can people actually buy these machines.

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**Author:** ![mike-lawrence](https://yyz2.discourse-cdn.com/flex030/user_avatar/discourse.mc-stan.org/mike-lawrence/32/59_2.png) [@mike-lawrence](https://discourse.mc-stan.org/u/mike-lawrence)\
**Post date:** [August 5, 2021, 5:19pm UTC](https://discourse.mc-stan.org/t/lightmatter-cpus-and-stan/23820/5 "2021-08-05T17:19:34Z")

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They have some really good articles on their stuff [on medium](https://link.medium.com/NXs38hnMtib).