HPE ProLiant Compute DL325 Gen12 review: A deceptively small and powerful 1P rack server with a huge core count

HPE's ProLiant Compute DL325 Gen12 offers businesses a great alternative to more costly dual-socket (2P) rack servers. Supporting most of AMD's Gen5 EPYC CPUs, this single-socket (1P) server can squeeze up to 192 cores into only 1U of rack space.

Targeting a wide range of enterprise workloads, including hybrid cloud, containerized environments, and virtualization, it takes everything we liked from its predecessor, the ProLiant DL325 Gen11, and makes it even better. For starters, DDR5 memory capacity has been doubled to an impressive 6TB, and the DL325 Gen12 sports HPE's new iLO7 remote management controller.

Storage capacities remain the same as the DL325 Gen12 also supports up to four LFF, ten SFF, or 20 E3.S EDSFF NVMe SSDs, but the server is available with HPE's new multi-purpose drive bays, allowing you to mix and match different storage devices. HPE's NS204i-u V2 hot-pluggable boot-optimized storage device can now be mounted at the front or the rear, as can the OCP expansion slots.

HPE ProLiant DL325 Gen12 review: Build quality and cooling

Chassis built quality is excellent, and the server presents a tidy internal design offering easy access for upgrade and maintenance tasks. Our system was supplied with a 32-core 3.55GHz EPYC 9355P CPU mounted centrally, topped off with a large passive heat sink and flanked on each side by banks of 12 DIMM slots.

The server currently supports 23 different EPYC models ranging from 8 up to 192 cores, but choose your CPU carefully as there are significant cooling requirements. Those with TDPs up to 240W can use the standard heatsink and cooling fans, while models between 260W and 300W (which includes our CPU) need the performance versions, with all configurations requiring a full house of seven fans.

For CPUs with TDPs of 320W and upwards, you must specify liquid cooling, and the good news is the server supports HPE's nifty closed-loop liquid cooling system. We've seen this in action when we reviewed the DL325 Gen11 and found the kit takes up very little room as the CPU cold plate with integral pump has two coolant pipes routed directly to a full-width radiator mounted between the cooling fans and the drive backplane.

HPE recommends replacing the liquid cooling kit every five years, which is now field replaceable. The new iLO7 management controller also introduces a coolant leak detection feature, which wasn't available in the iLO6.

HPE ProLiant Compute DL325 Gen12 review: Storage and expansion

The chassis may only measure a shade under 67cms deep, but HPE has packed it full of storage and expansion goodness. Our review system was supplied with eight SFF drive bays, a single tri-mode backplane that supports SATA, SAS4 plus NVMe SSD devices, and a blanking plate to the right that can be replaced with an extra dual-drive SFF cage or a DisplayPort/USB/optical drive enablement kit.

Other storage configurations are a four LFF drive backplane or the hybrid storage solution, which comprises up to five drive boxes, with each one supporting two SFF drives or four EDSFF E3.S NVMe SSDs. The GPU-optimized chassis supports up to four 75W single-width or two 400W double-width GPUs, leaving room at the front for two drive boxes with either four SFF drives or eight EDSFF E3.S SSDs.

AMD's chipset doesn't offer any integral RAID features, so you'll need to specify one of HPE's Smart Array Gen11 (there are currently no Gen12 models) controller cards, which are available in PCIe or OCP versions. We didn't need a RAID card in our system as it had four 3.84TB NVMe SSDs with the backplane direct-attached to the motherboard's M-XIO connectors.

The multi-purpose drive bays also support front-mounted OCP NIC cards and HPE's NS204i-u V2 boot-optimized storage device. We had the latter installed at the rear and fitted with two hot-plug 480GB M.2 NVMe SSDs to provide mirrored redundant storage for running an OS or hypervisor.

There's plenty of room to grow as the server has two rear risers, each offering PCIe Gen5 x16 expansion slots. Underneath lurk two OCP 3 PCIe 5 slots, which support HPE's 'o' RAID cards and a good range of network adapters.

HPE ProLiant Compute DL325 Gen12 review: iLO7 management

Remote management sees big changes as HPE's new iLO7 controller delivers tougher platform security and supply chain integrity. Furthermore, unlike the DL360 Gen12 we recently reviewed, the iLO7 is implemented in this server as an OCP-compliant DC-SCM (data center secure control module) board.

The iLO7 silicon root of trust (RoT) digital firmware fingerprinting is future-proofed to protect against next-generation quantum computing threats, and it introduces HPE's patented Secure Enclave. This is a physically tamper-resistant security processor that stores sensitive data such as encryption keys, passwords, and security configurations.

The new iLO7 web console is designed around workflows and offers a customizable home page dashboard that can present up to six cards. These have color-coded icons showing details such as security issues and server health, and each one provides hot links so you can quickly drill down to see more information

We run HPE's OneView 10.2 in the lab on a Hyper-V host and had no problems importing the DL325 Gen12 for on-premises management and monitoring. The iLO7 also connects directly to HPE's GreenLake Compute Ops Management (COM) cloud service which provides a complete overview of your server estate plus tools for server deployment and management, automated system lifecycle compliance and AI-powered insights.

HPE ProLiant Compute DL325 Gen12 review: Is it worth it?

Businesses balking at the cost and power demands of dual-socket rack servers will find HPE's ProLiant Compute DL325 Gen12 offers a very cost-effective alternative. The top TDP EPYCs will require liquid cooling, but this single-socket server combines a high core density with an impressive memory capacity, teams them up with a versatile range of storage features, adds HPE's highly secure iLO7 controller, and delivers it all in a surprisingly small package.

HPE ProLiant Compute DL325 Gen12 specifications (as reviewed)