Lenovo 4XB0G88734 600GB SAS 15K HDD: Specs and Server Compatibility
Is there still a case for a 15K spinning drive when SSDs exist? For a lot of workloads, no. For a specific set of them, yes - and the reasoning is worth understanding before writing off the category.
The Lenovo 4XB0G88734 is a 600GB SAS 12Gb/s 15K 2.5-inch drive for ThinkSystem and System x servers. It is the fastest class of mechanical storage, and where it still gets specified, it is usually for reasons of cost per gigabyte at a required IOPS level rather than raw speed.
Where 15K still beats flash on cost
Flash wins on latency by an enormous margin. That is not in dispute. The question is what you pay per gigabyte to get there, and whether your workload needs it.
For a mid-sized database or a virtualisation host with moderate IOPS requirements, an array of 15K SAS drives frequently delivers adequate performance at a fraction of the cost per gigabyte of enterprise SSDs with equivalent endurance ratings. Where the working set is large but the IOPS demand is moderate, that arithmetic still favours spinning media.
There is also the write endurance question. Enterprise SSDs are rated by drive writes per day, and a write-heavy workload needs a mixed-use or write-intensive drive at a significant price premium. A mechanical drive has no equivalent wear limit - it fails mechanically over time rather than wearing out through writes. For sustained write-heavy workloads that do not need flash latency, that removes a whole cost dimension.
None of which argues against flash for latency-critical work. It argues for matching the tier to the requirement instead of defaulting to the newest technology.
4XB0G88734 specifications
| Part Number | 4XB0G88734 |
| Manufacturer | Lenovo |
| Capacity | 600GB |
| Interface | SAS 12Gb/s |
| Rotational Speed | 15,000 RPM |
| Form Factor | 2.5 inch SFF |
| Drive Class | Enterprise Performance |
| Condition | Refurbished, function-tested |
| Warranty | 30-day TechSellerUSA warranty |
The IBM to Lenovo transition, and what it means for parts
Lenovo acquired IBM's x86 server business, which is why ThinkSystem and the older System x platform share a great deal of engineering. It is also why sourcing drives for these servers can be confusing.
Some drives carry IBM part numbers, some carry Lenovo ones, and the two ranges overlap in the transition period. A server bought as a System x may take drives listed under either brand depending on when it was configured.
The reliable approach is to identify the drive part number currently fitted rather than working from the server model. Pull a drive, read the label, and order against that. Our Lenovo range and IBM range both list by exact part number so you can match either way.
Caddy generations: G2HS and G3HS
Lenovo and IBM used different hot-swap carrier generations, and they are not interchangeable.
G2HS trays came first; G3HS superseded them. A drive supplied in a G3HS caddy will not seat correctly in a chassis expecting G2HS, and the reverse is equally true. This is the most frequent cause of a correctly specified drive arriving and failing to fit.
The check is straightforward: pull an existing drive from the chassis and compare the tray to the one on the drive you intend to order. If you are ordering from a supplier, quoting the part number of the drive currently fitted is the surest way to get a match, since the part number encodes the caddy along with the drive.
SKU: 4XB0G88734 | Refurbished & function-tested | 30-day warranty
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This drive is small form factor, and that is not incidental.
A 2U server chassis holds roughly twice as many 2.5-inch bays as 3.5-inch ones. In a performance tier where IOPS scale with spindle count, that doubling is the difference between an array that meets its target and one that does not. Twenty-four small-form-factor 15K drives in a 2U chassis deliver considerably more parallel I/O than twelve large-format drives could.
Small-form-factor drives also draw less power and generate less heat per unit, which matters when a chassis is fully populated with 15K spindles - a rack of them produces meaningful thermal load.
The trade-off is capacity per drive. Large-format nearline drives reach far higher capacities, which is why capacity tiers use 3.5-inch and performance tiers use 2.5-inch. Trying to use one form factor for both roles compromises whichever tier loses out.
Ordering
We supply the 4XB0G88734 refurbished and function-tested with a 30-day warranty, single spares or in volume for array population. If you are unsure whether your chassis takes G2HS or G3HS carriers, send us the part number from a drive currently fitted and we will confirm the match. The complete enterprise hard drives catalogue is online.
Common questions
Does a 15K hard drive still make sense against an SSD?
For workloads with a large working set but moderate IOPS demand, often yes - an array of 15K SAS drives delivers adequate performance at a fraction of the cost per gigabyte of enterprise SSDs with equivalent endurance. For latency-critical work, flash wins clearly.
What is the difference between G2HS and G3HS caddies?
They are different hot-swap carrier generations and are not interchangeable. A G3HS drive will not seat correctly in a chassis expecting G2HS and vice versa. This is the most frequent cause of a correctly specified drive arriving and failing to fit.
Should I look under IBM or Lenovo part numbers?
Possibly both. Lenovo acquired IBM's x86 server business, so the ranges overlap during the transition period and a System x server may take drives listed under either brand. Identify the part number of a drive currently fitted rather than working from the server model.
Why use 2.5 inch drives in a performance array?
A 2U chassis holds roughly twice as many 2.5-inch bays as 3.5-inch ones, and in a performance tier IOPS scale with spindle count. Small-form-factor drives also draw less power and generate less heat per unit, which matters when a chassis is fully populated with 15K spindles.
Do mechanical drives have a write endurance limit like SSDs?
No. Enterprise SSDs are rated by drive writes per day and a write-heavy workload needs a costlier mixed-use or write-intensive model. A mechanical drive fails over time rather than wearing out through writes, which removes a cost dimension for sustained write-heavy workloads that do not need flash latency.
Send us the part number from a drive currently in the chassis and we will confirm caddy compatibility before quoting.
