The Dell XPS 8650 became extremely slow after the fan upgrade.
The Dell XPS 8650 became extremely slow after the fan upgrade.
Hello All,
I bought a Dell XPS 8650 about a year ago, and the annoying noisy fan began to activate in the PSU. After some investigation, I learned about the unique design of the power supply. Rather than buying a new one from eBay, I opted to swap out the two inexpensive fans with Noctua models, assuming they would fit well due to their 3-wire setup. Once I received them, I connected the old wires to the new ones, double-checked everything, and reassembled the unit. When I restarted the computer, it slowed significantly—games like The Forest and ARK Survival had to pause before opening folders and loading files took minutes.
I disassembled the PSU again and verified my connections. It turned out two thin wires from the new fans had detached from the heat shrink and were making contact. I unplugged the fans completely and reattached them. The computer still ran sluggishly. I checked the BIOS for any resets or errors, found nothing unusual, and reviewed event logs with no suspicious activity. The built-in hardware diagnostic also reported no faults, even after the fans were removed.
I then tried replacing the NVME SSD to see if it was the culprit. After doing so, the performance remained poor. I found a link to the latest Userbenchmark results here:
https://www.userbenchmark.com/UserRun/65159442
I inspected the 10-pin PSU connector for irregular voltages, but all 12V pins read 12.4V—no significant fluctuations detected. It doesn’t seem logical that the PSU would cause such a slowdown. I’m puzzled as to what else I should inspect or replace to resolve this issue. Should I consider swapping the motherboard (which might also mean replacing the case and PSU), or should I focus on the processor? The benchmark indicates the CPU is the bottleneck, but could it be due to a faulty motherboard? Thank you all for your guidance!
Are you encountering an error during startup regarding the CPU fan being disconnected? As previously discussed, Dell uses a lot of unique proprietary connectors and components (occasionally). Based on your specifications for the UBM, it might be beneficial to upgrade to a mid-range or higher motherboard with BIOS updates for 13th/14th generation, a new case and power supply, and transfer other hardware to the new system. This could potentially affect your OS license, so I recommend checking your MS account before proceeding with any changes.
There was no issue with the CPU fan; it appears the two internal fans on the power supply are currently unplugged, making it unlikely the Mobo would detect them and trigger an error. The concern might actually lie with the processor. I wouldn't want to replace everything just yet, as that could lead to further complications. Thanks!
It's really hard for me to understand.
Could you check the temperatures?
Edit - Dell offers a tool named Optimizer that can provide additional details and recommendations. Usually I don't install it long-term, but it could assist in identifying the problem.
Hey Punkncat,
Sorry for the slow response. Initially, I attempted to use the Optimizer program, but it seems these specific XPS machines aren't compatible (boo). I checked the temperatures via HWInfo, and the CPU remains around 25-28 Celsius even during stress tests with CPU-Z. I opted for a small water cooler from Dell, and it appears to be working well so far.
If you'd like, I can include a short log file of sensor readings or the HWInfo report here.
Thanks again for your help!