Why don't motherboards support the highest RAM Speeds?

Like always with overclocking, it is not guaranteed to work or be reliable. When one as a hardware manufacturer makes a claim about supported speeds, there's a lot of things to consider:

• Does it work within the whole specified temperature range?

  Which is perhaps something like 0° to +85°C for a motherboard. They'll have to make the guarantee for what whole range, while in practice your motherboard might be some 30-50°C most of the time.

• Under which premises was it tested for electromagnetic compatibility (EMC)?

  The speeds used in the test will have to be used in the real product or else the CE/FCC marking turns invalid and the product may turn illegal, as it might cause electromagnetic interference (EMI) with other devices or turn vulnerable against EMI. These are major concerns for high speed buses.

• Is the hardware clock provided accurate enough to support the speed?

  All data communication is based on clocks from oscillators, some manner of crystal oscillator in this case. An oscillator is picked based on which speeds you wish to support and what inaccuracy you may tolerate. Too bad clock margins mean that the data sent risk getting corrupted. Which in this case would lead to way slower speed, rather than faster.

These are all hardware design decisions to be made in advance. Good engineers always design with margins, which is why overclocking is a thing - the part may work reliably outside the specified range up to a certain point where it doesn't.

The most probable error mode of RAM would be data corruption, in which the worst case is that the OS might decide that it should lay down and die (BSOD etc). You aren't going to cause any hardware damage by it. You may however provoke unexpected side effects like "coil whine" in some hardware, when you go outside the tested frequency ranges. PSUs are prone to this for example. Coil whine is harmless most of the time, but obviously very annoying.

posted 27 days ago

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Lundin‭

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With overclocking, it's probably just the standard caveats:

• It might damage your hardware (although this seems unlikely for merely changing memory speeds)
• Your software might become unstable (BSODs and crashes out of nowhere)
• Not every unit is equal, so you might have to keep returning products and buying new ones until you get the lucky one

I don't know any specific reason why they would support one speed but not another slightly faster one. Usually, a few months later the same manufacturer will release a similar product that does support the faster speed. So it is clearly not difficult to do.

My guess would be that when a new speed becomes common in the consumer market, the manufacturer doesn't want to slow down product development by telling all the in-progress products to halt and update their design. Only product cycles that begin afterwards incorporate the new speed, and even then, they don't always bother. A simple release of a new processor or memory chip is also not enough for them to decide to support it - they might be waiting for some nebulous "consumer traction" first. So they lag behind the latest speed by about the length of their product development cycle.

Generally, memory speed doesn't seem to matter much for performance and most consumers don't care about it much. A lot of those that do care, don't actually understand what it does, but just believe the marketing, which can be done regardless of technical features. So there's not much reason for manufacturers to be very strict about supporting the fastest memory speeds.

Also, looking at their products as a whole, these companies seem pretty hit and miss. I think it's not a stretch to conclude that they are, to some extent, mismanaged and have incompetent product managers. We can't expect them to release products that perfectly fit the needs of the market even if they wanted to.

posted about 2 months ago

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matthewsnyder‭

1047 reputation 32 35 142 34

Depending on your use case - historically RAM speed hasn't mattered that much. AMD's APUs were memory speed dependent, but that was for the video adaptor. It's also worth noting many PC builders tend to be enthusiasts, and there's always been a overclocking scene. Binning, and selling ram that runs faster is just good business sense.

I'm a big fan of Puget Systems' blogs for things like this. They do a ton of real world testing, and they've done benchmarks going into detail about the impact of faster/OCed RAM.

The advantage is you can squeeze small amounts of extra performance, either using automatic or manual overclocking methods. However the 'default' speeds are going to be stable. You'd be getting 5-7% performance improvement but also risking application and OS instability.

The 'native' non OC speeds are what the manufacturers tested and know work reliably. In some cases either because it's a newer board, or the manufacturer found it's better for the system.

posted about 1 month ago

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1mo ago by Michael‭

Journeymangeek ‭

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