Hello! My name is Justin. I'm a computer science student and teaching assistant at UNT currently studying computer microarchitecture. My thesis is about reducing the amount of duplicated values in the GPU L2 cache for GEMM-based 2D convolution by utilizing a smarter cache mapping function with a side-cache holding extra metadata. This will allow us to reduce the size of the cache without reducing performance!

Besides that, I'm also interested in other broad kinds of microarchitecture research. The types of problems I like to solve are creating brand-new computers that are really good at solving domain-specific problems. Small-scale problems (e.g., targetting a specific part of the computer like the L2 cache) are familiar to me, but I really want to branch out towards full-system architecture by changing many different parts of the computer all at once in brand-new ways! I want to work on projects that completely change the way computers operate!

My current work at UNT with GPUs looks like this:

• Propose changes that can be made to some part of the GPU microarchitecture.
• Modify the source code of GPGPU-Sim to reflect this change.
• Create benchmarks to run on the simulator that demonstrate the benefits and downsides of my changes.
• Construct figures that show what happens when different key components of the architecture is changed on these benchmarks (e.g., "how does the speed/memory accesses/hit rate change when the number of LSHRs/registers/L1 size changes?").

I'm currently applying to PhD programs for Fall 2025 or Spring 2026, but my day-job is to work as a software engineer at xAI. My job mainly consists of creating software that X's LLM, Grok, can use to improve in performance. Outside of work, I'm researching GPU computer architecture for accelerating deep learning applications.

Click the sidebar to see my CV (and a more-condenced resume) along with specific examples of my research and other projects. You can also find my experience teaching, including as a private tutor, instructional assistant, and teaching assistant. Besides computers, I like to spend my free time folding cranes and reading. Feel free to contact me at justingarrigus@my.unt.edu about inquiries.