add arrow-down arrow-left arrow-right arrow-up authorcheckmark clipboard combo comment delete discord dots drag-handle dropdown-arrow errorfacebook history inbox instagram issuelink lock markup-bbcode markup-html markup-pcpp markup-cyclingbuilder markup-plain-text markup-reddit menu pin radio-button save search settings share star-empty star-full star-half switch successtag twitch twitter user warningwattage weight youtube

Ryzen 3800X Overclocking

jeevion
  • 6 months ago

I built this, it is now up and running:

PCPartPicker Part List

Type Item Price
CPU AMD Ryzen 7 3800X 3.9 GHz 8-Core Processor
CPU Cooler Deepcool GAMMAXX L240 69.34 CFM Liquid CPU Cooler
Motherboard MSI B450 GAMING PRO CARBON AC ATX AM4 Motherboard
Memory G.Skill Ripjaws V Series 32 GB (2 x 16 GB) DDR4-3200 Memory
Storage ADATA XPG SX8200 Pro 1 TB M.2-2280 NVME Solid State Drive
Video Card Asus Radeon RX 580 8 GB ROG STRIX Video Card
Case Fractal Design Meshify C ATX Mid Tower Case
Power Supply SeaSonic FOCUS Plus Gold 650 W 80+ Gold Certified Fully Modular ATX Power Supply
Prices include shipping, taxes, rebates, and discounts
Total $1206.44
Generated by PCPartPicker 2019-08-19 15:05 EDT-0400

I have two Arctic P12 PWM PST CO 120mm mounted on the radiator instead of stock fans from the L240 top-mounted. I have two Arctic P14 PWM PST 140mm mounted on the front of the case as intake. The memory is a 32GB Dual-Rank B-Die kit (now running 3733 with 15-15-15-38 timings).

With bios on auto, the 3800x runs Cinebench R15 at an all-core of 4.1-4.2GHz, and when on idle I see it boosts up to 4.4-4.45 (only saw 4.5 once). With bios set manually 1.28v I'm able to run 4.3GHz all-core and it is stable. I had the chip running at 4.5GHz all-core but that required up to 1.48v and this cooler can't move enough heat fast enough - which brings me to the problem.

In Prime95 using maximum heat generation option with 16 threads it usually instantly crashes the system unless I am running auto voltage and freq. Here such a test will all-core down to 3.9 and stay about 72c, which is fine. But when I try running say 4.4 with even 1.28 and run the same test, usually an instant restart. I think the problem is once the CPU gets a load that the cooler can not keep up with, there is a runaway effect that starts going over 90c and reboot. The 4.3 all-core @ 1.28v has been running 100% stress (CPU-Z utility) on all threads for about an hour and no problems.

So I am wondering what others use to test for possible worst-case-scenario load/thermal stability? This Prime95 seems to force a reboot unless the cpu can throttle down to 3.9, which it does on auto. The problem is Cinebench seems to run no problems at all whereas once Prime95 moves into any maximum heat test, computer reboots. I've had a lot a reboots because of this test - it took me a while to understand it was the cooler being brought to its knees. Thank you for help and advice.

Comments

  • 6 months ago
  • 2 points

If you are getting an instant crash (not seeing temps spike) trying to run Prime95 it is not the cooler. It's more likely your voltage drops across all the cores just enough to cause errors and the crash, aka Vdroop.

I had a similar issue with my Ryzen 5 2600. Running 3.9 GHz at 1.2v I was stable for everything except Prime would often lock up the system, not right away, but at various time through a run. Increasing my voltage to 1.225v solved the issue.

Sort

add arrow-down arrow-left arrow-right arrow-up authorcheckmark clipboard combo comment delete discord dots drag-handle dropdown-arrow errorfacebook history inbox instagram issuelink lock markup-bbcode markup-html markup-pcpp markup-cyclingbuilder markup-plain-text markup-reddit menu pin radio-button save search settings share star-empty star-full star-half switch successtag twitch twitter user warningwattage weight youtube