R360 Not As Fast As It Should Be. Tried All Settings - Can't Improve Benchmarks

Hi,

 

Thank you for reaching out to us. I understand your concern regarding the server performance and tuning. Unfortunately, our support scope is limited to hardware-related issues that appear in the system logs.

For performance tuning and optimization, we recommend to wait for your post to be replied by the experienced users and experts can provide guidance.

 

On a side note, you might be right on OS version and kernel. If you found out more when you installed Rocky 9, do share with the public of the outcome. 

Thank you for your reply Joey. I hope someone can help here as I am really disappointed with this new purchase.

I have just spent all weekend testing different O/Ss, tweaking and benchmarking. The results for this R360 are underwhelming and not what I expected for such a decent specified server.

tl;dr Yes there is an issue with Rocky / RHEL 10, but more significantly Dell are severely hamstringing the server and not allowing it to run at it's full potential.

Rocky / RHEL / Alma 10 / Kernel 6.12 Retrograd Performance Hit

There is an issue with version 10. There are various reports that this version causes 15-25% drops in performance compared to version 9. This is very unusual, because version 10 has much better support for this modern hardware, has better performing schedulers, and better optimisations.

Most of the reports point to losses involving memory throughput (read / write operations). Changes in read-ahead buffering and other storage tweaks have caused sequential read performance to degrade. The EEVDF scheduler (introduced in kernel 6.6 and present in 6.12) aims for better fairness and latency but can cause regressions in CPU-bound workloads, especially single-core or mixed tasks on Intel CPUs.

I think my server suffers mostly from that last part because most of my apps are single threaded and this is where I have the biggest performance drop (over the other server I have - the non Dell E-2388G).

I proved that Rocky 10 was part of the problem by running sysbench cpu and memory in single thread mode. For Rocky 10 the cpu scores are around 4000, but for version 9.6 I could get 4400, which is slightly better than the E-2388G but the point is that there is a perfomance hit for using Rocky 10 compared to Rocky 9.

I tried a later kernel. I loaded up 6.17 kernel-ml from elrepo. It made absolutely no difference. All the benchmarks remained the same.

More O/S

I tried Rocky 9.6 again, to see if I had made a mistake somewhere. The 10 regressions / slow downs had gone (and I was back up to 4400 sysbench for CPU but the R360 is still not as fast as it should be.

I then tried Alma Linux 9. That was identical to Rocky with no improvements. I couldn't get any difference in speed with the various tuned profiles and all other techniques I used to optimise a server were just not doing anything.

I then tried Windows 11. I thought maybe this R360 doesn't like Linux. Maybe the 6349P doesn't like Linux. Maybe the Linux O/S doesn't like the 6349P. It was worth a try.

I loaded up Windows 11 and ran a few benchmarks such as CPU-Z and Geekbench 6. Whilst the scores I obtained were fair they were ranking the same as i7-12700k for CPU-Z and the Geekbench scores were similar to an i5-13600K, so not very impressive.

Both those chips have max turbos of 5.0GHz and 5.1GHz respectively. And so it seems that is the case with this "5.7GHz" 6349P which is installed in Dell's R360. It's a knobbled chip. Dell prevent it from running at it's best speed.

Dell Hamstringing the Hardware

I have had Dell's for decades. I have either co-lo'ed my own or used dedicated servers and they were great. Back in 2019 I went away from Dell to a different manufacturer. Now back with Dell it seems I am out of the loop because I never knew that in that time Dell had started to cap the turbo speeds. Rather than get 5.7GHz (which they advertise as when you are using the configuration builder) the best you can get is 5.1Ghz. This is what I am getting on Linux and on Windows. Take a look at these images:

That shows the max clocks, core temps and power after running CPU-Z benchmark. Note that the max clock is 5.1GHz and the temps are fair and well below the max for the chip. In the next image light work was done:

Here the temps are much lower and again 5.1GHz is the limit!

Why Is This?

No really why? I don't get this temperature throttling nonsense. The ambient temperature in here is 20', I have tried the server with Max Fans setting (which sounds like a 747 taking off) and yet the 5.1GHz is solid. 

This IS the biggest problem for me. The 5.7GHz chip just won't go above 5.1GHz. It is like buying a car that has a speed limiter on it but the sales guy does not tell you that. He says 'It can do 125Mph' but when you take it home you then realise it can't go that fast despite the engine manufacturer stating it's all good - run it at it's max stated speed all day.

I feel ripped off here. Unless I can get a solution to this I am going to have to scrap this project and go back to the other manufacturer.

So before I do that does anyone have a possible solution? Is there any script out there that over-rides the speed limiters? Is there any hardware tweak? I thought DPAT would be a solution but after loading up the 30 day trial licence there is nothing in iDRAC that indicates it is available to me. Is this because i have iDRAC basic and need enterprise?

Last call for a solution before I give up on this Dell.

Hello,

 

First I'll state what Joey mentioned that we don't do performance tuning.

 

We would run the built in diagnostics (in the LifeCycle Controller) and confirm there are no hardware faults.

 

Please let us know is you have if you have any faults or failures.

 

Have you checked the LifeCycle and System Event Logs for any faults or failures?

 

I'm sure you already check but I'll ask if you have all the system firmware up to date?

 

You may try testing outside the OS with our SupportLive tool

Support Live tool:

The latest version of SLI: http://downloads.dell.com/FOLDER02725522M/1/SLI22_A00.iso

 

Maybe someone in the community has tried and can share their experience.

 

Thank you for your reply Charles. I can confirm there is no hardware fault with this server - the diagnostic tests pass, and there is nothing in the logs that indicate a hardware problem. All firmware is upto date as of 20th Nov 2025.

The issue is that the profile for the CPU turbo settings are too restrictive, which means that this Xeon 6349P chip is running slower than my old E-2388G.

Unfortunately it seems Dell is not willing to resolve this, which means I feel totally let down and I feel I have been mis-sold something that was promised to be faster but was not.

I won't be buying Dell again.

Hello,

 

Please note Dell Technical support does not provide performance tuning. We do provide break and fix support for issues that can result in poor performance. We can make sure diagnostics show no hardware faults and firmware and drivers are up to date. You have indicated that you have verified those.

 

We do have this Community where any member can share their experience performance tuning.

Thank you for your prompt reply Charles. I appreciate you have a job to do, and that you have to follow specific guidelines. But in case there is any doubt about this here is the issue:

Dell undertune this platform. The CPU is supposed to hit 5.7GHz but Dell prevent that from happening. This is the point I am trying to make. Dell are the problem here: not tuning, not software, not O/S. Dell.