Selecting a GPU for a Dell T620

/ Christopher Paquin

I just recently posted about installing a GPU Power Supply Expansion Board into the Dell T620. I suggest giving that post a read before you continue, as this will be post builds upon what was discussed previously. This post will be a bit of a deep dive into what you should consider when choosing a GPU for your T620.

Ok, so first things first, you need to choose a GPU that is compatible with your T620, as not everything is going to work. Choosing a GPU that is a good fit for your workload, well that comes second.

Let’s start by looking at what Dell tested and certified.

Officially Supported GPUs for the T620

ManufacturerModelHeatsinkPower Usage
NvidiaTesla C2075Active215W
NvidiaQuadro K4000Active80W
NvidiaQuadro Q6000Active204W
NvidiaTesla K20AActive225W
ATI™ FirePro™V7800Active150W
AMD FireProW7000Active127.7W

According to the documentation, only the above GPUs are “supported” on the Dell T620. Note that this really means that these are the only cards that Dell certified/tested. It does not mean that there are not any other compatible cards out there. These GPUs are honestly quite old. The only still relevant use case for any of them in this day and age is video transcoding on the quadro card. However, you might be able to do some lightweight AI/ML work on the Tesla K20A (2688 Cuda Cores, Kepler Architecture)

Dell documentation further expands on what is supported. Specifically…

  1. Up to four 300W, full-length, single- or double-wide GPU cards
  2. GPUs with up to 6GB of dedicated DDR5 memory
  3. GPUs that are actively cooled.
  4. No more than 2 power connectors per card
  5. Power connectors located on the back of the card
  6. GPU enablement kit (Power & Cooling Required)

Additionally Dell documentation states the following…

  1. All cards are the same make/model
  2. 1000W power supplies are required (technically for systems with more than 2 cards)
  3. You need not to cram your T620 too full with GPUs and Raid Controllers to avoid overheating

What About other GPUs?

So this is where we start to go off the rails, and venture into the unknown. Let’s start with what we know, which is what Dell officially supported and what their documentation says about choosing a GPU

Is 6GB the VRAM Limit?

At the time, Dell only were able to test and certify a handful of GPUs, and none of those GPUs had more than 6GB of VRAM. So it’s very possible that this is why Dell documentation tops out at 6GB as supported. I doubt this is an actual real-world limit.

The T620 was released in 2012 and probably went end-of-life in 2017 – 2019. None of the officially “supported” cards were released after 2013. Available GPUs with more than 6GB VRAM were probably not widely available, and if they were, Dell probably had finished their initial round of GPU certification and moved on to better things. Any GPUs with more than 6GB would probably run hotter and consumed more power, which could be an issue. Additionally there could be conflicts at the firmware/bios level for mapping/managing more than 6GB of VRAM. Who knows? Generically, they probably drew the line at 6GB because “that is what they knew worked”.

What about Power and Cooling?

Adding GPUs to a system will increase cooling and power needs. Replacing existing PSUs, with 1000w PSUs (as recommended by Dell) is very simple and actually pretty cheap. I think I picked up mine for less than $30 USD a pair on ebay. Dual 1000w PSUs was the only supported configuration if you wanted to order a T620 with GPU. However, you still needed to get that power to the GPUs themselves.

This is where the GPU Enablement Kit comes into play. The enablement kit consists of…

  1. Power expansion board
  2. GPU Power Cables
  3. A Fan Gantry (shown below)
T620 Fan Gantry

The fan gantry is not easily found, and they are expensive. You will probably spend more on one of these that you did for your T620. They run about $300+ USD on ebay.

I have found 3 part numbers on line

  1. 0VDY5 – fan
  2. 8G79K – gantry
  3. 2R4DV – Fan + Gantry?

The fan gantry from a T630 will also work as well, albeit with a couple of slight modifications. As you need to cut a bit of metal, took me about 2 minutes to modify mine with some tin snips.

The TOP square I modified a slight bit with tin snips. You will need to do the same for a 4 squares

Note that you will need T620 Fans, as the T630 fan plugs do not line up with the power receiver on the motherboard (hence why you need to modify the gantry)

T620 Fan on the left. T630 Fan on the right. Notice the offset of the power plug is different between the two server models.

Note that the Fan Gantry for the T630 is not any cheaper, it’s just a bit easier to find . The part number for the T620 fan is 0TW71C, which is the same fan that are at the rear of the baffle.

Adding non-Dell proprietary fans to the chassis of the T620 is either much harder or much more expensive, as most of the unused power connectors in the chassis are proprietary. There are also no standard mounting brackets for common fan sizes.

However, there is power to be had. There is connector coming off the drive backplane that provides SATA power to the CDROM. And in theory you could do this…

Male Sata–Female Molex == Male Molex–Female Molex == Fan Controller with 2pin Molex

Now you can add a fan controller and can add some more fans, but you will have to get creative. A few pci slot blower fans? PCI slot Graphics Card Cooler possibly?

Similar Alternative GPUs with Active Cooling

Assuming we need to keep to similar power usage and VRAM, let’s look at a few older, yet not as anemic GPUs.

1. NVIDIA GeForce GTX 1660 Super

  • VRAM: 6GB GDDR6
  • TDP: 125W
  • Cooling: Actively cooled
  • Performance: Great for basic AI/ML tasks, especially if you are focused on inference or lighter training workloads.

2. NVIDIA RTX A2000 (Professional Card)

  • VRAM: 6GB GDDR6
  • TDP: 70W
  • Cooling: Actively cooled, compact design
  • Performance: A professional GPU tailored for AI/ML workloads and well-suited for power-constrained environments.

3. NVIDIA T1000

  • VRAM: 4GB GDDR6
  • TDP: 50W
  • Cooling: Actively cooled, compact design
  • Performance: Suitable for lightweight AI/ML applications and inference tasks, ideal if energy efficiency is a priority.

What about GPUs without External Power

No power supply expansion board?

Let’s look at GPUs that do not require external power. Most PCIe 3.0 slots provide only 25 watts of power, however 75W is the maximum power delivery from a single PCIe 3.0 slot. The Dell T620 has 4 such X16 slots. This alone is appealing and is one of the reasons the Dell T-Series are popular with home labbers. By contract, my newer R630 only provides max of 25W per PCIe slot.

T620 Power Provided Per PCIE Slot

SLOTPOWERCPU CONNECTION
Slot 1 (x8 lanes)up to 25WCPU1
Slot 2 (x16 lanes)up to 75WCPU1
Slot 3 (x4 lanes)up to 25WPlatform Controller Hub
Slot 4 (x16 lanes)up to 75WCPU1
Slot 5 (x16 lanes)up to 75WCPU2
Slot 6 (x8 lanes)up to 25WCPU2
Slot 7 (x16 lanes)up to 75WCPU2

GPUs that run on 75W or less

Below is a list of possible GPUs that you can run without additional power requirements, other than what select PCIe slots in the T620 will provide.

NVIDIA GPUs

1. NVIDIA Tesla T4

  • Performance: Excellent for AI inference and light training.
  • Power: 70W (fits within PCIe 3.0 constraints).
  • VRAM: 16GB GDDR6.
  • Features: Tensor Cores, CUDA support, and FP16/FP32/INT8 capabilities for AI/ML.
  • Notes: Designed for data centers and supports efficient AI workloads.
  • Cooling: Passive (gets super hot)

2. NVIDIA Quadro T1000 / T2000

  • Performance: Entry-level professional GPUs for AI tasks.
  • Power: 50-75W.
  • VRAM: 4GB-6GB GDDR6.
  • Features: CUDA cores and optimized drivers for compute tasks.
  • Notes: Focused on balanced performance and efficiency.
  • Cooling: Active

3. NVIDIA GeForce GTX 1650 (Low Profile/Standard)

  • Performance: Suitable for light AI/ML workloads.
  • Power: 75W.
  • VRAM: 4GB GDDR5/GDDR6.
  • Features: CUDA support for training and inference.
  • Notes: Ensure you get a variant without external power connectors.
  • Cooling: Active

4. NVIDIA GeForce GTX 1050 Ti

  • Performance: Basic AI/ML tasks and experiments.
  • Power: 75W.
  • VRAM: 4GB GDDR5.
  • Features: CUDA cores and basic AI capabilities.
  • Notes: An older but efficient card for small-scale projects.
  • Cooling: Active

AMD GPUs

1. AMD Radeon RX 6400

  • Performance: Entry-level GPU for basic AI workloads.
  • Power: ~53W.
  • VRAM: 4GB GDDR6.
  • Features: RDNA 2 architecture with good efficiency.
  • Notes: Limited AI-focused features but sufficient for lightweight tasks.
  • Cooling: Active

2. AMD Radeon Pro WX 3200

  • Performance: Professional GPU for light compute tasks.
  • Power: 50W.
  • VRAM: 4GB GDDR5.
  • Features: Optimized drivers for professional workloads.
  • Notes: Reliable for basic AI workloads and professional use.
  • Cooling: Active

Intel GPUs

1. Intel Arc A310

  • Performance: Basic GPU for lightweight AI and inference.
  • Power: ~75W.
  • VRAM: 4GB GDDR6.
  • Features: Support for AI frameworks like TensorFlow and PyTorch.
  • Notes: Newer entry from Intel with decent AI potential.
  • Cooling: Active

What about Modern GPUs?

Let me start out by saying that it’s possible that many present day GPUs might actually operate without issue in the T620. That being said, what you risk is the bios/lifecycle controller throwing an error as it does not like what it sees happening in its slot. 

A bus fatal error was detected on a component at slot 7

Above is the error that I encountered attempting to run a Telsa T4 card. I attempted with several different 16x slots, and the error moved with each slot that I tried. This error usually resulted in an OS kernel panic. In my case, its possible that the Nvidia T4, being passively cooled, could have been part of the problem, the card was too hot to touch. Although temperature could have had nothing to do with it and the card may just not “work” in the T620 (at least not yet, as I continue to troubleshoot)

Regarding newer cards, through my research I have found that a number of folks have had good luck with a few different CPUs (See Reference Section Below). Bottom line, you may get lucky.

Myself, well I am not giving up on getting the Nvidia T4 to run in my T620. I still have a some experimentation to do. Mainly some bios config tweaking and a bit of add on cooling. I also have some ideas regarding the lifecycle controler, but I have yet to test anything.

Troubleshooting/Stability

Below are a few ideas that I have regarding troubleshooting, good luck. I will create a new post at some point in the near future regarding my sucess with the Nvidia T4 GPU.

  1. Slot Disablement  – disable unused PCIE slots. PCIE power stability is especially important
    • “Boot Driver Disabled”. Will investigate this setting. This allow the slot to be visible to the OS, but will not be available as a boot device.
  2. BIOS upgrade – make sure you are running the latest bios (2.9.0)
  3. PCI Slot Selection – choose 16x slot closest to a CPU.
    • I have seen that many have success in slot 5
  4. Cooling – Make sure your GPU is not getting too hot.
    • Pull hard disks to improve air flow on the right side of chassis
    • PCI slot cooler
    • PCI slot blower
  5. Disable Dell Lifecycle Controller?
  6. Disable Collect System Inventory On Restart (CSIOR)?

Conclusion

Bottom line, these machines were not exactly designed to run with GPUs, and only a handful of GPUs were actually tested and supported on the Dell T620. The list of supported cards is short, and these GPUs are quite old. However, just because its not supported, does not mean that it will not work. It just means it was not tested. Your mileage may vary. I’ve seen a number of post from individuals who are running more modern GPUs the T620 and they do so without issue.

Dell Documentation

  1. Dell PowerEdge T620 Technical Guide
  2. Dell T620 GPU Card Installation Guidelines and Requirements

Reference

  1. Is X7C1K compatible with T620
  2. T620’s device manager recognizes GTX780Ti, but programs do not “see” the card?!
  3. T620 gpu issue
  4. PowerEdge T620: 6-pin PCIe power connector not working (GTX 1060 3GB & GTX 680)
  5. T620’s device manager recognizes GTX780Ti, but programs do not “see” the card?!
  6. GTX 1080 not working in T620
  7. Adding GPU for display – Dell T620 and T630 (change from UEFI to BIOS?)
  8. Dell T620 GPU > use kit from T630? (Radeon HD5770. Confirmed T620 kit works in T620)
  9. Adding GPU to Dell T620 (1660 ti and a 750 ti.)
  10. Dell EMC PowerEdge T640: Remove/Install GPU PIB (Pretty much the same as the T620)



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