Intel Core i9 X-Series 9900X 10-core LGA 2066

The i9-9900X posts a 21,602 PassMark multi-thread score, putting it in the 78th percentile of our database. That's genuinely impressive for a chip this old, but the 165W TDP and 54.7 efficiency score mean it runs hot and thirsty. At $168 on the used market it's a steal; at $500 it's a pass.

The multi-thread score of 21,602 is the headline here. That puts this chip well above average in our database, and it's the reason anyone still considers the 9900X in 2025. With 10 cores and 20 threads at a 4.4GHz boost, it handles parallel workloads like video encoding and 3D rendering without flinching. The quad-channel memory controller is a real advantage over mainstream platforms, letting you push up to 128GB of DDR4.

Single-thread is a different story. The 2,534 PassMark score is solid but unremarkable, sitting in the 71st percentile. For gaming, that's fine, but you're leaving frames on the table compared to newer architectures. The AVX-512 support is a nice bonus for scientific workloads, though it comes at the cost of even more heat. And speaking of heat, that 165W TDP means you'll want a serious cooler. The 4.4GHz boost is achievable, but only if your thermals are in check.

Against the AMD Ryzen 7 9800X3D, the 9900X loses badly in gaming and efficiency. The 9800X3D's 3D V-Cache gives it a massive advantage in frame rates, and it does it at a fraction of the power draw. The 9900X's 10 cores give it an edge in heavily threaded productivity, but the 9800X3D's 8 cores are no slouch either. Compared to the Dell Xeon E5-2637 V2, the 9900X is in a completely different league, with roughly double the cores and far better single-thread performance. The Xeon is a server pull that belongs in budget homelab builds, not a workstation. The 9900X sits in an awkward middle ground: too old to compete with modern flagships, too expensive on the used market to be a no-brainer budget pick.

Value is where this gets complicated. The 9900X originally launched at a premium, and even now the used and remaining stock market is all over the place. In the US, prices swing from $168 to $500 across three listings, which is a massive spread. If you can snag one at the low end, that's actually a compelling deal for a 10-core chip with quad-channel memory. At $500, you're better off looking elsewhere. The budget score of 64.8 out of 100 reflects this inconsistency. The best US deal at $168 makes this a budget workstation monster, but you'll still need to factor in the cost of an X299 board, which isn't cheap either.

The Core i9-9900X is a 10-core, 20-thread Skylake-X chip that still holds its own in multi-threaded work, landing in the 78th percentile of our database with a PassMark score of 21,602. That's a solid showing for a CPU that's been around the block, and it means this thing chews through renders, compiles, and heavy multitasking without breaking a sweat. The 19.25MB of L3 cache and quad-channel DDR4 support give it real bandwidth for workstation tasks.

But here's the catch: efficiency sits at just 54.7 out of 100, and that 165W TDP tells the story. This is a power-hungry chip that runs hot and demands a beefy cooler and an X299 motherboard. Single-thread performance is decent at 2,534 on PassMark, but it's not going to impress anyone coming from a modern mid-range chip. You're buying this for the core count, not the efficiency.

Skip this if you care about efficiency or single-thread performance. The 54.7 efficiency score and 165W TDP mean higher electricity bills and more heat in your room, and the 2,534 single-thread PassMark score lags behind even budget modern chips. If you're building a new system from scratch, the cost of an X299 motherboard plus this CPU will likely exceed a newer platform that performs better in every metric. Gamers should especially look elsewhere, as the single-thread performance will bottleneck high-refresh-rate gaming.

The i9-9900X is a capable 10-core workhorse that still delivers strong multi-threaded performance, but it's a tough sell in 2025 unless you find it at a steep discount. The 21,602 PassMark score proves it can still handle serious workloads, and the quad-channel memory support is genuinely useful for content creators. But the 165W TDP, aging single-thread performance, and the cost of the X299 platform make it hard to recommend over newer options. If you already have an X299 board and need more cores, this is a solid upgrade. If you're building from scratch, look elsewhere.