PCIe 5.0 Storage, Two CPUs, One Clear Winner?
PCIe 5.0 SSDs promise dramatically faster sequential read and write speeds compared to their Gen 4 predecessors, but whether a CPU platform can fully feed that bandwidth depends on more than just the spec sheet. Testing the AMD Ryzen 5 9600X against the Intel Core Ultra 5 245K with a high-end PCIe 5.0 drive reveals exactly where each platform delivers – and where it quietly falls short.
Platform Differences That Actually Matter for Storage
Both processors support PCIe 5.0 natively, but the way each platform handles storage bandwidth differs at the architecture level. The Ryzen 5 9600X sits on AMD’s AM5 platform, which routes PCIe 5.0 x4 lanes directly from the CPU to the primary M.2 slot. There is no intermediary controller between the drive and the processor, which keeps latency low and bandwidth consistent under sustained workloads. The Core Ultra 5 245K on Intel’s LGA1851 platform also provides direct CPU-attached PCIe 5.0 x4 for the primary M.2 slot, so both platforms start from a structurally similar position on paper.
Where the gap appears is in how each platform manages the surrounding I/O infrastructure. Intel’s Z890 chipset adds additional PCIe lanes via the chipset link, but the primary NVMe slot is the only one running at full Gen 5 speeds from the CPU directly. AMD’s X870E boards offer a similar arrangement, though board manufacturers have been more aggressive in providing multiple Gen 5 M.2 slots via dedicated routing on higher-end X870E designs. For this test, we kept both platforms running a single Gen 5 drive in the primary CPU-attached slot to eliminate board-level variables.
CPU memory subsystem performance also plays a role in storage throughput, particularly in random access workloads where data moves through system cache before hitting RAM. The 9600X uses AMD’s Zen 5 architecture with 32MB of L3 cache across six cores, while the 245K uses Intel’s hybrid Lion Cove plus Skymont design with P-cores handling the heavy compute lifting. In raw memory bandwidth, the 245K’s dual-channel DDR5 configuration at DDR5-6400 XMP tends to edge out the 9600X at comparable DDR5-6000 EXPO settings, which can influence drive-to-memory transfer benchmarks in subtle ways.
The test drive used here is a current-generation PCIe 5.0 x4 NVMe SSD rated for sequential reads above 14,000 MB/s and sequential writes around 12,000 MB/s – figures that represent roughly double what a fast Gen 4 drive can sustain. Thermal throttling on these drives is a real concern, so both test systems used motherboards with active M.2 heatsink cooling to keep temperatures within the drive’s rated operating range throughout extended benchmark runs. Without adequate cooling, even the best Gen 5 drive will pull back speeds noticeably after the first few minutes of sustained reads.
Benchmark Results: Sequential, Random, and Real-World
In sequential read testing using CrystalDiskMark 8, both platforms hit near-rated speeds, with the 245K system averaging around 14,200 MB/s and the 9600X system coming in at approximately 13,950 MB/s. That gap is narrow enough to fall within test variance, and neither result points to a meaningful CPU-side bottleneck. Both processors have enough PCIe bandwidth headroom that the drive itself – not the platform – is the limiting factor in sequential workloads. Sequential write results followed a similar pattern, with both platforms sustaining speeds above 11,800 MB/s consistently across five test runs.
Random 4K performance is where storage benchmarks get genuinely interesting for day-to-day PC use. Loading game assets, accessing project files, and running operating system tasks all lean on random read IOPS rather than sequential throughput. In ATTO Disk Benchmark and AS SSD testing, the 245K platform posted slightly higher random read IOPS, a margin that correlates with its stronger memory subsystem performance and the way Intel’s memory controller handles small-block transfers. The 9600X closed that gap almost entirely in random write IOPS, where Zen 5’s cache architecture appears to buffer write commands more efficiently under bursty workloads.
For real-world testing, game load times in titles like Cyberpunk 2077, Microsoft Flight Simulator, and Star Wars Outlaws were measured from menu selection to full in-game render. None of these titles currently saturate even PCIe 4.0 bandwidth during a standard load sequence, which means the differences between the two CPU platforms in this test were measured in fractions of a second. Microsoft Flight Simulator showed the largest gap at roughly 0.8 seconds faster on the 245K system, likely due to the CPU’s stronger memory bandwidth handling the simulation’s aggressive asset streaming rather than the storage platform itself.
File transfer benchmarks using large mixed-media folders told a more practical story. Moving 50GB of video files from the Gen 5 SSD to a secondary Gen 4 drive on the same system stressed both the storage bus and the CPU’s ability to manage simultaneous read-write operations. The 9600X handled this scenario with slightly lower CPU overhead – hovering around 4 to 6 percent CPU utilization during the transfer – compared to the 245K’s 6 to 9 percent range. For a six-core chip competing against a ten-core hybrid design, that efficiency figure is worth noting if storage-heavy workloads are part of your regular use case.
Power consumption during peak sequential read testing was another meaningful data point. The 9600X platform drew less total system power during storage stress tests, which speaks to Zen 5’s efficiency at the platform level rather than raw performance. The 245K consumes more wattage across the board, and while that feeds stronger peak burst performance in CPU-intensive tasks, it does not meaningfully translate to faster storage outcomes. If your primary interest is storage performance specifically, paying the power premium for the 245K does not give you proportional returns on a Gen 5 SSD setup. We tested both CPUs head-to-head in gaming workloads previously – see the full Ryzen 5 9600X vs Core Ultra 5 245K 1080p gaming comparison for how those results stack up against this storage data.
What This Means for a PCIe 5.0 SSD Build
If you are building a system specifically to take advantage of a Gen 5 SSD, either platform will deliver the drive’s advertised sequential performance without bottlenecking. The differences between the 9600X and 245K in storage benchmarks are real but narrow – narrow enough that platform cost, cooler compatibility, and DDR5 kit pricing will have a bigger impact on your total build cost than the CPU’s storage throughput contribution. The 9600X’s lower power draw and platform efficiency make it a practical choice for builds where the Gen 5 SSD is the centrepiece investment rather than an afterthought.
Where the choice becomes less straightforward is if your workload combines heavy random I/O with compute tasks that scale with core count and memory bandwidth – video editing with concurrent file access, 3D rendering while streaming assets, or large database operations. In those combined scenarios, the 245K’s memory subsystem advantage becomes more consequential, and the storage performance gap between the two platforms widens slightly in sustained mixed workloads. For pure gaming builds with a Gen 5 SSD, the load time difference between both platforms currently amounts to less than the time it takes to read a loading screen tip.
Frequently Asked Questions
Does the Ryzen 5 9600X bottleneck a PCIe 5.0 SSD?
No. The 9600X routes PCIe 5.0 x4 lanes directly from the CPU to the primary M.2 slot, delivering near-rated sequential speeds without a platform bottleneck.
Is the Core Ultra 5 245K faster with a Gen 5 SSD than the Ryzen 5 9600X?
Marginally in random read IOPS and memory-bandwidth-heavy transfers, but the gap is too small to justify a platform choice based on storage performance alone.
