The AMD FX processor is restricting my 1866 MHz RAM to 1333 MHz. What options do I have?
The AMD FX processor is restricting my 1866 MHz RAM to 1333 MHz. What options do I have?
After a considerable pause from playing on PCs (almost ten years), I finally chose to return and assembled a fresh setup. I thoroughly investigated parts and examined all the reviews for each item at my preferred online shop—something that reminded me of my egg habit…—before making any purchases. Keeping costs in mind, I bought components that appeared solid with some flexibility for future upgrades, without becoming overly attached. Once I became fond of my new machine, I quickly realized it was time to enhance my modest RAM and graphics setup to match the maximum capacity of the motherboard, along with a significantly improved card. Here are the essential parts I’m currently using:
Mobo: GIGABYTE GA-990FX-Gaming AM3+ AMD 990FX SATA 6Gb/s USB 3.1 USB 3.0 ATX AMD
Processor: AMD FX-6300 Vishera 6-Core 3.5 GHz (4.1 GHz Turbo) Socket AM3+ 95W FD6300WMHKBOX
Power Supply: CORSAIR HX Series HX750 750W ATX12V 2.3 / EPS12V 2.91 SLI Ready CrossFire Ready 80 PLUS GOLD Certified Modular Active PFC Power Supply
RAM: CORSAIR Vengeance LP 32GB (4 x 8GB) 240-Pin DDR3 SDRAM DDR3 1866 (PC3 14900) Desktop Memory Model CML32GX3M4A1866C10
Video Card: ASUS GeForce GTX 1070 DUAL-GTX1070-O8G 8GB 256-Bit GDDR5 PCI Express 3.0 HDCP Ready SLI Support
I overlooked one crucial point, though. It wasn’t until a friend and I were examining the BIOS for something unrelated that we noticed the RAM clocked at 1333 MHz instead of the claimed 1866 MHz. Since then, I’ve read extensively and discovered that AMD FX processors typically struggle with 1866 MHz RAM at default settings, consistently limiting it to 1333 MHz without much adjustment. While several forums suggest tweaking the BIOS to allow 1866 MHz, many report numerous complications. The most useful links I found are on Corsair and GigaByte sites. Most advice centers on a few adjustments:
- Switch the memory profile from Auto to Profile1 and set the frequency to 1866.
- Modify the timings to something like 9-10-9-27 and adjust the voltage to 1.5V.
These suggestions are common, but applying them often results in the system failing to boot, displaying an error window that blocks startup and prompts BIOS access.
I’m generally confident in building PCs from scratch, but I’m not an overclocker. Experimenting with voltages, frequencies, and timings isn’t something I feel confident about. Ideally, I’d just let my RAM run at the rated speed if possible. I was hoping someone experienced in these details could offer guidance. Treat me as a beginner here—even simple steps might be missed due to my limited knowledge.
For example, would it matter if I installed only two sticks at once and tested them first? Then add the other two? I’m not sure how to proceed.
Appreciate any tips or advice you can share.
Tekton1980 shared his experience about memory settings. He bought two 4GB 1600MHz Corsair sticks and noticed an automatic adjustment to 1333MHz upon insertion. He matched the BIOS RAM settings to the stick defaults, which worked without errors in memtest. He believes the issue arises only when using dual-channel mode with all four RAM slots. He provided a link for more details.
When all memory channels are used you'd be limited to 1600MHz because of memory controller in the processor. That's a limitation on all FX chips. Try first with only 2 RAM chips and see how it goes. You may need to raise RAM voltage a bit too.
I purchased two 4GB 1600MHz Corsair modules and when I first connected them, they automatically adjusted me to 1333MHz. I only changed my BIOS settings to match the stick defaults, and everything has worked smoothly without any issues in memtest or anything.
i bought 2 4gb 1600MHz corsair sticks and when i first inserted it automatically put me at 1333Mhz, but all i did was matched my bios ram settings to the ram sticks defaults and i've been fine ever since with no errors in memtest or anything so.. yeah, i think that if you're using just one channel (the two matching slots), the fx processors can run at full power. If my understanding is right, the problem only comes up when you switch to dual-channel mode and use all four slots.
Tekton1980 shared his experience about memory settings. He bought two 4GB 1600MHz Corsair sticks and noticed an automatic adjustment to 1333MHz upon insertion. He matched the BIOS RAM settings to the stick defaults, and everything worked smoothly without errors in memtest. He clarified that the issue likely arises when using dual-channel mode with all four RAM slots active. He provided a link for more details on memory frequency guidelines.