Gigabyte G493-ZB3 GPU Server Review
March 21, 2025We have the Gigabyte G493-ZB3 GPU Server, which is an NVIDIA certified system, and it is a performer! At 4U, it features dual AMD EPYC 9004 or 9005-series processors with up to 160 Zen 5 cores, less cores if you go with the 9004 series CPUs, but we will get to that. This is a large server with room for up to 8x GPUs, and quite a bit of memory!
As you know, AI is big in Information Technology right now, and the Gigabyte G493-ZB3 GPU Server delivers an impressive set of features to tackle AI, AI Training, AI inference, visual computing and high-performance computing applications. With a 4U chassis, dual processors, support for up to 48x DIMM modules and up to 8x double-wide PCIe GPUs, it can deliver on that AI promise.
On the front of the system are 12x 2.5-inch hot swap storage bays that can be outfitted with SAS-4, SATA, and Gen5 NVMe storage devices. There are 2x low profile PCIe Gen 5 x16 slots on the front of the system and a control panel at the bottom of the chassis with 2x USB 3.2 Gen 1 slots, a dedicated management port, VGA port and 2x 1GbE ports.
Squeezed in between the RJ45 ports and the VGA port are a few LEDs and buttons including a unit ID button, the power ON button, both with integrated LED. Next, HDD LED, System Status LED, then buttons for Reset and Non-Maskable Interrupt.
On the back of the Gigabyte G493-ZB3, there’s not much, 4x PSUs featuring 1 + 3 redundancy. To the right you can see the PCIe slots on the bottom for the GPUs and a row of 8x PCIe slots for low-profile PCIe cards. That’s it, as the control panel is located on the front of the system.
That integrated management port provides access to Gigabyte’s pre-installed Management Console. The Gigabyte Management Console is free-of-charge and accesses the ASPEED AST2600 management module installed on the system board. The Management Console will enable you to manage this single system or a small cluster. If you need more comprehensive management of several servers, say in a data center, then you can download the Gigabyte Server Management suite. GSM is compatible with IPMI and Redfish standards and includes several utilities to make life much easier for system Admins.
Once we lift off the cover panel, you can see the basic setup with the CPUs and memory modules staggered behind the 12x 60mm fans just behind the drive backplane. With a staggered formation, there is a x4 PCIe slot on each side for support of an M.2 drive. One on the side of CPU0, and the other one on the side of CPU1. With just one M.2, you can boot the system. With two M.2 drives installed you can boot the system with redundancy in a mirrored RAID for resilience.
Where it gets interesting is with the GPUs, so let’s start with that by lifting the lid, so to speak. That lid, is comprised of 8x low profile PCIe slots and can be used for network communications or perhaps a SAS controller. The back slots tilt up to expose the full-height, full-length PCIe 5.0 slots underneath where the double-wide GPUs can be installed. By the way, all slots are PCIe 5.0 x16 slots for full bandwidth. The CPUs support up to 128 PCIe lanes per CPU, but only 160 PCIe 5.0 lanes with both processors installed.
We know, you feel a little like you got shortchanged on that but you didn’t. There are 20x PCIe x16 slots, not to mention the 2x x4 M/2 slots. That adds up to more than 2-times the number of PCIe 5.0 slots available from the CPUs. However, PCIe switches (Broadcom PEX89144) connect to those low profile PCIe x16 slots on top, and then there’s another set of PCIe switches for the GPU board down below. The switches ensure an orderly, and efficient stream of data from the CPU to the PCIe devices both top and bottom, essentially increasing the overall bandwidth utilization. The front PCIe switches are actually not in the switch loop, and are directly under CPU control.
On the bottom, you do have a few choices for GPU support from AMD, NVIDIA, Xilinx, and Qualcomm. From AMD, there is only the Instinct MI210 with 64 GB of HBM2e memory and 6,656 processor cores. There are more NVIDIA GPGPUs that are qualified to run on this system, including the NVIDIA A100, H100, H100 NVL, L40, and L40S. For graphics-intensive applications, the NVIDIA RTX 6000 Ada Generation. The real stand-outs here for AI applications are the H100 NVL with 94 GB of memory and the H100 with up to 80GB of HMB3 memory. Both feature Hopper architecture with the H100 NVL given a slight edge with support for more memory and a dual GPU design that supports NVLink connectivity for greater memory bandwidth than the H100.
On top, and in front, you can install a choice of network controllers and hard drive controllers for RAID or HBA. You’ll still need a controller if you want SAS drives. You can also choose an NVIDIA BlueField-2 DPU card to improve the efficiency of your network communications. It does that by offloading some of the traffic that would ordinarily go through the CPU and is fully programable. Some of these are very fast but Gigabyte only mentions one, with a SFP56 interface on a Gen 5.0 PCIe x8 card with dual ports at 25Gb/s, per port. No worries. There are other options with faster network communication speeds.
Dual CPUs are supported on the Gigabyte G493-ZB3. If you want access to all of the memory, storage, and PCIe slots, then both CPUS are required. Otherwise, you’re at half full—of everything. And who wants that with something link this? We figure you can still get the management features too with only CPU0 installed. But again, why? So, dual sockets compatible with 4th and 5th generation AMD EPYC processors. Originally, it only supported 4th Gen CPUs but with Rev. 3.0 you get support for 5th Gen CPUs.
4th Gen CPUs provide up to 128 Cores and 256 threads per CPU compared to up to 160 cores and 320 threads with 5th Gen AMD EPYCs. Yes, 5th Gen will go up to 192 physical cores and 384 virtual threads but the Thermal Design Power rating on this system is limited to 400W per CPU so you won’t be able to install the 192-core top of the line 5th Gen CPU as that one has a TDP of 500W. Still, at 160 cores and 320 virtual threads per CPU, quite impressive! The 4th Gen EPYCs top out at 360W, so not a problem with TDP across the family. That said, depending on your workload or maybe more importantly in the short run, your budget, you may not need all those cores. 5th Gen actually go from 8 cores up to the 160 cores. Physical cores. Double that for virtual cores. With 4th Gen you get 16 cores up to the 128 cores with the 9754s and 9754.
All of these CPUs deliver 12-channel memory architecture and support up to 24x DDR5 RDIMMs per socket. Memory speed is limited to 4800 MT/s with 1DIMM per Channel (1DPC) with 5th Gen CPUs or up to 4400 MT/s with 4th Gen. Memory speed will be reduced with 2x DIMMs per channel. At full capacity with 256GB modules in all slots, the Gigabyte G493-ZB3 can support up to 12 TB of memory.
With dual 5th Gen AMD EPYC CPUs, a full complement of memory, and 8x high-performance GPUs installed, you’re good to go on a number of high-performance computing scenarios or AI applications. We tried to make this brief given our tendency for too much information, but if you have any questions post them in the comments section below. Need more clarification or just looking for a completely different system or parts? Contact us today!
