Why your high-speed RAM might be running at a snail's pace

By Joe Rice-Jones

10 minutes ago

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When carefully picking out parts for your PC build, you'll notice that your RAM was marketed with AMD EXPO and Intel XMP as one of the significant features. DDR5 will have one or possibly both of these mentioned, while DDR4 will have XMP or say they're compatible with AMD's Ryzen platform, but whatever the naming scheme, they all behave similarly. They're profiles for frequency, timings, and voltage that the RAM kit will use in the BIOS to try and boot with the best performance, but there's a catch.

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The XMP/EXPO system seems like it should be foolproof, but it's not, and those speeds aren't necessarily guaranteed. It's often a quick fix to get near them, though, and successive BIOS updates might make your motherboard compatible with the high speeds of your RAM.

What are EXPO and XMP?

And why aren't they guaranteed success

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DDR RAM is a very complex system of signals to store and read data at very high speeds. XMP (and later, EXPO), was created to take the difficulty out of manually overclocking your RAM, as a one-click option with pre-defined profiles for that RAM kit.

Typically, RAM kits will boot at the JEDEC defaults, which are inching higher as DDR5 is here, but they're still much lower than a carefully overclocked kit of RAM can manage. XMP and EXPO are ways for manufacturers to test and build kits that reach higher speeds and lower latencies out of the factory, with one setting in the BIOS being enabled.

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They're still technically overclocking, even if they're manufacturer sanctioned

XMP and EXPO are potential gains, but they're far from guaranteed depending on the CPU and motherboard in your build, and that's why they're not enabled by default. Of course, it only takes a few seconds to boot into the BIOS and enable the relevant setting. However, that takes the onus away from the manufacturer, as it becomes a user-initiated change. That way, you're responsible if it doesn't boot, and there's every chance of that depending on the components you picked out.

Here's what to test first if your PC won't boot

Some combination of these main settings will let you run XMP or EXPO smoothly

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Whether your PC is using an Intel or AMD CPU, the process for getting XMP/EXPO to boot is very similar. After all, they're different versions of the same type of overclocking profile, and the checks are all the same.

Some of these fixes require knowledge of a few BIOS settings, which can be found in your motherboard's manual. Others will be on the product page on the manufacturer's website, and a couple are physical checks. None of them are particularly difficult, so you have a good chance of getting near to the XMP or EXPO settings, even if you can't quite make it to them. And sometimes, all you have to do is wait for a BIOS update to improve compatibility:

• Two sticks vs four: Most platforms have trouble running at full speed with more than two DIMMs installed, so you'll probably need to tweak things
• Which slots you installed in: Check your motherboard manual to see which slots you should have RAM in, and ensure they've been pushed in fully
• Check the QVL: The manufacturer's page for your motherboard will have a qualified vendor list (QVL) for RAM that's been tested (it's not a foolproof list, but it helps)
• Basic functionality: Turn XMP or EXPO off and try to boot at JEDEC defaults
• Less aggressive profile: Many RAM sticks have several XMP or EXPO profiles, so try one of the slower speeds to see if that boots
• Frequency: Try selecting a frequency speed one or two rungs lower than the profile suggests
• DRAM voltage: Sometimes, the profile doesn't automatically increase the voltage for DRAM use. Find where it is for your specific motherboard and increase it to 1.35V (or to the voltage on your RAM packaging)
• BIOS updates: Check for newer BIOS updates, as many of these increase RAM compatibility
• Primary timings: The timings for your RAM might be the cause. Most of the time, loosening these to higher values will fix the issue, but I've had some sticks that prefer a tighter timing profile

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If you're still having issues with getting XMP or EXPO settings after all this, it's possible either the memory controller on your CPU isn't up to the task, or there's something wrong with the CPU, the motherboard, or the RAM sticks. It's worth contacting each of the respective manufacturers for troubleshooting steps that I might have missed, or ways to check if your hardware is faulty and requires an RMA replacement.

Remember, XMP and EXPO are overclocking profiles and aren't 100% guaranteed

In a perfect world, XMP and EXPO profiles would work every time, and provide the rated speeds and timings for your hardware. But minute differences in the manufacturing of RAM modules can have big effects, especially as the frequency rises, and it's not guaranteed that any overclocking profile will work. Even if that RAM kit has proved to work on one CPU and motherboard combo, it might still fail on the same combination of hardware for another user, because micro differences can be all the difference.

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In my experience, most kits can reach their rated speeds with a little tweaking, at least if they're on compatible hardware. But it's always good to know that it's not guaranteed, and while the manufacturer might help troubleshoot, there might be nothing they can do.