Guide · 4U rack GPU server
4U rack GPU servers for AI
The RackGPU line has three options: an empty 4U chassis with 8 PCIe slots, and two GPU servers that Radius builds on the same chassis with AMD Radeon AI PRO R9700 cards. Compare them by VRAM, memory bandwidth, model fit and price.
RackGPU 4U chassis
Empty 4U rack chassis: 8 PCIe slots, ATX / E-ATX / mATX boards, 3 × 140 mm fans, rack rails.
₺21,999 incl. VATLaunch price
Buy on RackDepo
Rack-GPU Pro 64GB
2 × R9700, 64 GB VRAM, 1,280 GB/s. Ryzen 9 7900, 32 GB DDR5.
$7,950 + VAT$9,540 incl. VAT
Buy on RackDepo
Rack-GPU Pro 128GB
4 × R9700, 128 GB VRAM, 2,560 GB/s. Threadripper 9960X, 64 GB DDR5 ECC.
$19,750 + VAT$23,700 incl. VAT
Buy on RackDepo
Form factor
Why 4U for a GPU server
A 4U chassis stands four rack units tall. RackGPU uses that height for eight PCIe slots, dual-slot GPU cards and three 140 mm fans at the front.
Three 140 mm fans take in cool air through the honeycomb front panel. In the Pro systems, the R9700 blower fans exhaust the heated air through the slot brackets, out of the chassis. In the Pro 128GB, 4 dual-slot cards fill the eight slots.
Comparison
Chassis, Pro 64GB and Pro 128GB
The chassis is the enclosure. The Pro systems are complete GPU servers on the same chassis.
| Comparison | RackGPU 4U chassis | Rack-GPU Pro 64GB | Rack-GPU Pro 128GB |
|---|---|---|---|
| Type | Empty chassis: you choose the board, cards and power supply | Assembled system | Assembled and tested system |
| GPUs | Your choice · 8 PCIe slots | 2 × AMD Radeon AI PRO R9700 | 4 × AMD Radeon AI PRO R9700 |
| Total VRAM | – | 64 GB | 128 GB |
| Memory bandwidth | – | 1,280 GB/s (2 × 640 GB/s, in parallel) | 2,560 GB/s (4 × 640 GB/s, in parallel) |
| Processor | – | AMD Ryzen 9 7900 · 12 cores / 24 threads | AMD Ryzen Threadripper 9960X · 24 cores / 48 threads |
| System memory | – | 32 GB DDR5-5600 (2 × 16 GB) | 64 GB DDR5-5600 ECC RDIMM server memory (2 × 32 GB) · upgradable to 512 GB |
| Motherboard | ATX / E-ATX / mATX support | B850 · AMD AM5 · ATX workstation motherboard | TRX50 · AMD sTR5 · E-ATX workstation/server class |
| Power supply | – | 1,600 W Platinum · single power supply | 2,500 W ATX 3.1 · 80 PLUS Platinum (230 V EU), ≥ 94% efficiency at typical load |
| Storage | – | 1 × 1 TB NVMe PCIe Gen4 SSD | 1 × 1 TB NVMe PCIe Gen4 SSD |
| Cooling | 3 × 140 mm fan support | 3 × 140 mm high-performance quiet fans | 3 × 140 mm high-airflow fans |
| Dimensions | 186 × 445 × 455 mm (H × W × D) | 186 × 445 × 455 mm (H × W × D) | 186 × 445 × 455 mm (H × W × D) |
| Warranty | – | 2 years Hardcare Basic | Hardcare Basic |
| Delivery | – | Within a week of the order | About one week after the order, assembly and testing included |
| Price | ₺21,999 incl. VAT (launch price) | $7,950 + VAT | $19,750 + VAT |
Model fit
Which models you can run
The Pro 64GB runs 70B-class dense models entirely in VRAM. To run 120B-class models in VRAM and serve more users, choose the Pro 128GB.
| Model | Weights | Pro 64GB · 64 GB VRAM | Pro 128GB · 128 GB VRAM |
|---|---|---|---|
| Nemotron Super 49B (dense) | ~26 GB | Runs in VRAM | Runs in VRAM |
| Llama 3.1 70B (dense) | ~40 GB | Runs in VRAM | Runs in VRAM |
| gpt-oss-120B MXFP4 | 66 GB | Runs with host RAM | Runs in VRAM |
| Qwen3.5-122B-A10B int4 | 71.5 GB | Runs with host RAM | Runs in VRAM |
| Qwen3.8-Flash-Next W4A16 | 169 GB | Choose the Pro 128GB | Runs with host RAM |
The table shows model weights only. More concurrent users need more VRAM; for multi-user setups the Pro 128GB leaves more headroom.
Speed
Memory bandwidth sets token speed
At every decode step an LLM reads all of its active weights from VRAM, so memory bandwidth caps the tokens per second. Each R9700 reads its own 32 GB of GDDR6 at 640 GB/s, and the cards work in parallel.
Pro 128GB measurements: Qwen3.5-122B-A10B int4, 1k input / 1k output tokens, tensor parallel across four cards.
Which one
Chassis or complete system
FAQ
Frequently asked questions
- What is a 4U GPU server?
- A rack server four rack units tall, built around GPU cards. The RackGPU 4U chassis measures 186 × 445 × 455 mm, has 8 PCIe slots and cools the cards with three 140 mm fans at the front.
- Which RackGPU should I choose?
- The chassis (₺21,999 incl. VAT) if you build the server yourself. The Pro 64GB ($7,950 + VAT) for 64 GB of VRAM on 2 R9700 cards. The Pro 128GB ($19,750 + VAT) for 128 GB of VRAM, 2,560 GB/s and 4 cards.
- Does a 70B model fit?
- By weight size, yes. Llama 3.1 70B needs about 40 GB, which fits in the VRAM of both Pro systems. The Pro 128GB leaves 88 GB of VRAM beyond the weights for KV cache and concurrent users.
- Which GPU do the Pro systems use?
- The AMD Radeon AI PRO R9700: 32 GB of GDDR6 on a 256-bit bus, 640 GB/s and 300 W board power per card. The Pro 64GB has 2, the Pro 128GB 4.
- Can I build my own GPU server in the chassis?
- Yes. The RackGPU 4U chassis takes ATX, E-ATX and mATX motherboards, has 8 PCIe slots and support for three 140 mm fans, and comes with adjustable rack rails. Launch price: ₺21,999 incl. VAT.
- Where do I buy, and how long is delivery?
- On RackDepo. Radius assembles the Pro 64GB and delivers it within a week of the order. The Pro 128GB ships about a week after the order, assembly and testing included. Pro prices are in US dollars, with 20% VAT added.
Buy
Order on RackDepo
Radius assembles and delivers the Pro systems. Place your order on RackDepo, and contact our sales team for configuration requests.
- RackGPU 4U chassis
₺21,999 incl. VATLaunch price
Buy on RackDepo - Rack-GPU Pro 64GB
$7,950 + VAT$9,540 incl. VAT
Buy on RackDepo - Rack-GPU Pro 128GB
$19,750 + VAT$23,700 incl. VAT
Buy on RackDepo
Questions: 0 (216) 344 54 64 · satis@radius.com.tr