Memory Not Right
Memory Not Right
The person owns an older system with an AMD Phenom II X4 945 CPU and a Gigabyte GA-970A-D3 motherboard. According to Google, the CPU supports DDR3 1333, while the motherboard claims up to 1800. The system has 2x 4GB DDR3 1333 RAM, but in CPUZ it only shows 1066MHz. Setting the RAM to AUTO 1333 in BIOS causes a blue screen during startup. The question is why this happens and whether adding a 2GB 1600MHz RAM would help or complicate things further.
It'll be seen later.
Don't worry, I don't recall. Enjoy yourself!
There aren't 1800 MT/s DDR3 speeds available. Instead, the available rates are 1866 MT/s. This indicates that the RAM speed at those rates isn't consistent. Just because MoBo supports up to 1866 MT/s DDR3 doesn't guarantee every DDR3 RAM at that speed will function properly. RAM must adhere to JEDEC standards, which for DDR3 begin at 800 MT/s, then progress to 1066, 1333, and 1600. Checking MoBo specifications reveals a memory QVL list on the Support page, listing various RAM DIMMs tested by MoBo and confirmed to work across those frequencies. While RAM not listed in this list might still function at its rated speed (such as 1866 or 1600), the likelihood is low. Mixing different frequency, timing, or capacity RAM with existing modules can lead to instability, potentially preventing the system from booting properly. In the best case, the system will default to the slowest stable option. For a detailed explanation on why combining different RAM modules isn't recommended, refer to this guide: https://forums. For DDR3 systems, the actual RAM frequency is less important, particularly because higher frequencies also increase latency, which can offset any benefits from faster speeds. A helpful short video on this topic is available here: https://www.youtube.com/watch?v=dWgzA2C61z4
I still possess several Phenom II X4 955 and 965 configurations built on Gigabyte boards. The standard JEDEC speed for DDR3 RAM is 1066MT/s, but it's possible to maintain a reliable system with two DIMMs at 1333MT/s. Clearly, something isn't quite right here.
Regarding higher memory speeds on a Phenom, the benefits are limited. I experimented with 1600MT/s for a brief time using less precise timings, but the optimal range is around 1333MT/s for many Phenom setups.
It would be wise to run MemTest86 on a pair of DIMMs at 1066MT/s to verify their integrity at this speed. This could reveal any issues that might become more apparent at higher frequencies. If your friend is attempting OCZ RAM at 7-7-7-20 1333MT/s and voltage settings between 1..65 to 1.90V (as suggested by OCZ), consider replacing it. I experienced persistent errors with OCZ DIMMs for years, which disappeared once I switched to Kingston products.
Adding two 2GB modules instead of four 2GB modules should improve stability at 1333MT/s. Running MemTest86 on these would be a good check, even though you'll only have four GB total.
I operate my 955/965 systems on XP, Windows 7, and Windows 10, not Windows 11. If you're using a JMicron SATA controller, you might not find a stable driver for Windows 10.
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I forgot to mention testing with memtest86 in my previous reply. It was just an idea when I wrote it but slipped out at the end.
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Memtest86 download link: https://www.memtest86.com/
Installation guide: https://www.memtest86.com/tech_creating-window.html
Recommended runs: 1 full pass (15 tests) is the minimum, 2 passes are better, and 4 passes are acceptable.
Time estimate: 1 full pass for an 8GB DIMM takes about 1 hour; 2x 8GB takes ~2.5 hours. With your system’s 2x 4GB, expect roughly 1.25 hours per pass or ~5 hours for 4 passes.
phenom restricts ram bandwidth to 1333MHz. To boost it, the northbridge must be overclocked; otherwise, even with a ram clock speed of 1866, the limit remains at 1333MHz.
Regarding memory overclocking, if the memory multiplier fails (as indicated by XMP), FSB overclocking should compensate since the maximum stable ram clock is linked to the northbridge clock.
Check each stick individually to determine if it can start and run at 1333.