A deep dive into Nvidia's Vera CPU and the Olympus cores that power it

www.theregister.com · 2026-08-02 · by Long Nguyen ·generic
88 custom cores, 176 funky threads, 1.5 TB of laptop RAM, and 1.8 TB/s of NVLink connectivity — this isn't your typical datacenter chip

A deep dive into Nvidia's Vera CPU and the Olympus cores that power it

DEEP DIVE For the first time, Nvidia has directly challenged Intel and AMD's CPU dominance. With the launch of Vera, the AI arms dealer aims to flog its standalone CPUs to as many hyperscalers and other cloud providers as it can.

Alibaba, ByteDance, Meta, Oracle, CoreWeave, Lambda, Nebius, and NScale have already signed up to deploy the chips in their respective clouds.

The follow-on to Nvidia's Grace CPU promises 88 custom Armv9.2 cores, 176 threads, support for up to 1.5 TB of LPDDR5X memory, and, critically, availability as a standalone platform independent of Nvidia's GPUs.

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But beyond that, and a mountain of marketing about how it'll be the best CPU for everything AI, Vera's inner workings have largely remained a mystery until recently.

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That changed late last month, when Nvidia released a whitepaper spilling the beans on its first fully-custom CPU, which is far weirder than anyone could have anticipated.

Ostensibly, Nvidia is aiming Vera at two key workloads: the first and least surprising is as the AI head node responsible for managing the GPUs in its upcoming Vera Rubin systems. The second, and more contentious, is as a host for AI agents, which, unlike the large language models (LLMs) that power them, don't actually run on GPUs.

From what we gather, much of Vera's core architecture is predicated on quashing pipeline and execution bottlenecks in order to make it more effective in these roles. But before we dive into Nvidia's Olympus core, let's revisit the chip itself.

Monolithic compute, multi-die memory and I/O

Block diagram of Nvidia Vera CPU architecture showing compute, memory and I/O chiplets.

Here's a quick refresher on Vera's construction.

Image credit Nvidia

Peel back Vera's rather substantial heat spreader and you'll find an assortment of chiplets responsible for I/O, memory, and compute. However, this isn't another rehash of the chiplet architecture popularized by AMD.

Unlike x86 processor makers, which spread dozens of cores across multiple dies, Vera's compute die is monolithic. All 88 cores are housed in one big chunk of silicon that from what we understand is fabbed on TSMC's 3nm process. Nvidia argues its monolithic compute architecture has benefits for both core-to-core bandwidth and latency compared to competing designs.

Surrounding the compute die is an assortment of chiplets, including eight LPDDR5x controllers, and what appears to be two distinct I/O dies, one responsible for PCIe 6.4 and CXL 3.1 connectivity and another dedicated to the chip's NVLink Chip-to-Chip interface.

In terms of package design, Vera is somewhat reminiscent of Amazon's Graviton 4 CPUs, which also combine a monolithic compute die while disaggregating the I/O and memory functionality to dedicated silicon.

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The Vera CPU Superchip

Nvidia’s Vera CPU superchip packs 176 cores and 3 TB of LPDDR5x memory.

Nvidia’s Vera CPU superchip packs 176 cores and 3 TB of LPDDR5x memory.

Image credit Nvidia

Like most modern datacenter CPUs, Vera supports both single- and dual-socket configurations, the latter of which Nvidia calls the Vera CPU Superchip.

Unveiled at GTC in March, the Superchip features two Vera CPUs connected over NVLink-C2C at a blisteringly fast 1.8 TB/s of bidirectional bandwidth, for a total of 176 cores and 352 threads.

The two chips are fed by 16 SOCAMM2 LPDDR5x memory modules, which deliver 2.4 TB/s of aggregate memory bandwidth (1.2 TB/s each) — roughly twice the bandwidth of AMD's Turin Epycs, which were launched in 2024.

Nvidia's agentic AI reference designs call for cramming as many as 128 of these superchips (256 CPUs) totaling 22,528 cores and 384 TB of memory into a single liquid-cooled rack.

Summiting Olympus

Previously, Nvidia had relied on off-the-shelf CPU cores from Arm. For example, depending on the iteration, Nvidia's Grace CPUs used Arm's Neoverse V2 (GB200/300), Neoverse V3 (AGX Thor), or Cortex X925 and A725 cores (GB10), depending on which was most convenient.

With Vera, Nvidia has moved on to designing its own ARMv9.2-compatible core, called Olympus. In fact, it's up for debate how custom the chip really is. We've been told that the chip builds heavily on existing Arm IP, and looking at Olympus' architectural block diagram, we can see why.

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Here's a block diagram of Nvidia's Olympus core architecture.

Here's a block diagram of Nvidia's Olympus core architecture.

Image credit Nvidia

Olympus features a 10-wide decoder and dispatch, eight integer arithmetic logic units (ALUs), six vector/FP pipelines (SVE 128), four load units, and 2x store units. So it's got a fat front and back end compared to the Zen 5 cores found in AMD's Turin Epycs or the Redwood Cove cores used by Intel's Granite Rapids Xeons.

But compared to off-the-shelf Arm cores, Olympus' front and back end aren't breaking any records. In fact, Olympus looks a lot like a heavily modified Cortex X925.

With that said, Nvidia claims Olympus features an entirely custom neural branch predictor, which is capable of exploring two branches simultaneously.

Branch prediction is key to performance in modern CPUs, and involves anticipating future code paths and executing down them before they're needed. By predicting two paths per cycle, Vera decreases the likelihood of a mispredict, theoretically boosting its performance in the process.

And from what we can tell, a lot of the customization that went into Vera was made explicitly to stamp out pipeline and execution bubbles in order to maximize the number of instructions per clock (IPC).

In particular, Nvidia claims its neural branch predictor delivers higher hit rates than history-based approaches, making it ideal for running branch-heavy workloads, like the Python scripts generated on the fly by AI code assistants.

Nvidia also claims to have made several innovations to the mid-core, again aimed at mitigating pipeline stalls. Memory renaming speeds up store-to-load dependency chains by allowing dependent instructions to execute before a load completes if the relationship to the data can be divined.

"This is particularly beneficial for pointer-heavy software, graph traversal, runtime frameworks, and complex object-oriented workloads," the company explained.

Nvidia also implemented a value prediction scheme which "identifies stable dependency chains and predicts future values before they are produced, allowing dependent instructions to execute speculatively while correctness is verified later."

This functionality, the company claims, helps to speed up repetitive software patterns and sequential data processing.

On the back end, Nvidia Olympus features a similar complement of ALUs and FP units as the X925, but they've been implemented differently. Eight of the ALUs are simple integer units which handle basic mathematics, while the company says two complex ALUs handle multiplication and division, CRC, and shift intensive workloads.

The back end also features four dedicated branch units that work with the chip's branch predictor to resolve control flow decisions that would otherwise cause pipeline stalls.

Meanwhile, for floating point operations, Olympus features six 128-bit Arm scalable vector engines (SVE2) extensions which also support FP8, along with a pair of vector units dedicated to speeding up crypto operations.

Each core is supported by a 64 KB L1 instruction cache, 96 KB L1 data cache, and 2MB per core of L2. The chip also features 164 MB of system level cache (SLC) that's sharded across the chip.

SMT makes a comeback on Arm

Perhaps Olympus' most interesting party trick is support for simultaneous multithreading (SMT).

SMT has been a mainstay of x86 chips since 2002. The technology boosts utilization by enabling two threads to harness idle execution units during a single cycle. While SMT doesn’t double throughput, for certain applications it can deliver double-digit percentage gains.

While Arm has supported SMT in the past — you may recall Cavium ThunderX2's four-way SMT implementation prior to its acquisition by Marvell — the company has downplayed its value with its own agentic CPU.

Arm's dislike for the tech didn't stop Nvidia from implementing SMT-like functionality in Olympus. We say SMT-like because it's not SMT in the conventional sense. Rather than simultaneous multi-threading, Nvidia markets it as spatial multithreading, which is an apt name given how it works.

From what we understand, Nvidia's SMT implementation is a bit more like core bifurcation than what Intel would call Hyperthreading.

From what we understand, Nvidia's SMT implementation is a bit more like core bifurcation than what Intel would call Hyperthreading.

Image credit Nvidia

Rather than two threads that share the resources of one core, Olympus' SMT implementation looks more like core bifurcation with a shared cache line. You can either have one fat core or two skinny ones. To our eyes, it looks a bit like multi-instance GPU (MIG) for the CPU.

The white paper makes a big to-do about how spatial multithreading avoids the thread contention you can see with x86 parts, which makes sense, because Nvidia's threads behave more like individual cores. We wouldn't read too much into these claims, though. There have always been applications that benefit from SMT and those that don't, and it's easy enough to turn it off if you don't want it.

With that, Nvidia's SMT implementation could be beneficial to agent sandboxes for agentic workloads. With containers — that's all these sandboxes really are – there are two workloads. There's the job you're running inside the container – let's say a Python script and interpreter – and then there's the container runtime, which is responsible for orchestration of container workloads and managing networking and storage overlays.

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