twoodfin
9 hours ago
I don’t think picking a handful of SPEC benchmarks that approximate today’s most common agentic workloads (compiling code, interpreting Python) and then calling them “agentic benchmarks” is misleading at all.
That you need a whole lot of “ordinary” compute to benefit from the scaling properties of agents is the reason Nvidia is making this chip in the first place.
jcranmer
7 hours ago
The four benchmarks selected are cppcheck, llvm, cpython, and gcc [1]. These are all essentially compiler benchmarks... and all of the compiler benchmarks in SPEC cpu2026! This makes the benchmark selection somewhat suspicious to me, since it's not particularly representative of a diverse set of workloads.
I also don't buy that it's a particularly representative set of tasks you might do with agents. Also included in the SPEC benchmarks are multimedia codecs, lossless data compression codecs, sqlite (i.e., database), all of which are going to be things you should easily throw into the sets of tasks an agentic workload might do. Cherry-picking just the compiler benchmarks instead of all of SPECint... again, it just raises a couple of eyebrows.
[1] To be honest, I'm kinda surprised that both gcc and llvm are in SPEC cpu2026.
fibonacci112358
7 hours ago
The code in compilers is the closest to your typical app you can get in a benchmark like SPEC, eveerything else is actually far more specialized. Compiler code is full of small basic blocks, lots of branches, indirect memory access; it's actually harder to get good performance for such code, both for CPUs and compilers (that was part of the death of Itanium too).
jcranmer
5 hours ago
That's true of most of the applications in SPECint (SPECfp is a different matter); there's nothing special about compilers there.
Where compiler code is going to get really unusual, I suspect, is that compilers tend to be a little mono-focused on relatively few data structures. I know I was able to get measurable (single-digit percent!) performance differences in LLVM making very small tweaks to layout in llvm::Value. By contrast, when I was working on Thunderbird, the only similarly small change I could think to make that kind of difference would be to "oops, all string functions are now a cross-DLL call" (and even then, only because string handling is so dominant in that kind of application). Another kind of difference is that the compiler-based benchmarks are going to be quite light in virtual or indirect function calls (there's more of an emphasis on switch-based dispatching than vtable-based dispatching in most compiler implementations), which is going to make it a poorer proxy for some kinds of applications.
lstodd
5 hours ago
Death of Itanium was that it was a) VLIW and b) Intel was too arrogant. So it went to the same destination as later Larrabee and ATI/AMD attempts at VLIW GPUs.
That is, nowhere.
Also you are wrong and anyone sizing up an arch to put their loads onto must first try that load on it and not rely on "bah, compilers compile on it".
pjmlp
2 hours ago
Itanium only died because AMD exists, and due to various licensing reasons they were allowed to come up with AMD64.
speed_spread
4 hours ago
VLIW works for DSP applications, it's not an instant dead end. It's a good fit in cases where code path and memory accesses are predictable, like shader code.