[T-Man]

I may be upgrading my PC soon and thinking it over reminded me of a warning a workmate gave me just before Christmas, about a quirk with DDR3 memory chips (might've been concerning them and Intels which was why he told me, am debating an i5 or i7). I only really know the basics about the hardware side of PCs (sadly think workmate thought I knew a lot) so was wondering if someone might have heard of it too and be able to make more sense of it as it sounded like a big thing. Wanted to spread word in general too for same reason.

So if I remember him correctly, it was to do with the run speed settings in BIOS, and DDR3 memory being designed to run at double the BIOS's speed. A quirk causes it to wrongly calculate (something about multiplying a value that's already been multiplied) and arrive at a value 2x or even 4x the intended speed, causing the memory to overclock itself into the ground (and sometimes even fry the PC). He said changing the BIOS settings would fix this problem and the PC would then run fine, apparently.

But yeah, was hoping someone here more knowledgeable may have heard about this somewhere and be able to explain better?

Thanks (and sorry if old news; meant to ask before Xmas)

[The E]

First time I heard of this. Sounds more like a bug in the BIOS, to be perfectly honest (or a misremembered anecdote). In general, the only thing you need to worry about when purchasing RAM is that it's rated for the same speeds your motherboard is (in the MB's spec sheet, you'll see something like "DDR3-2100" or so, that's what you should look out for), the rest will be handled by the MB when it boots.

[Fury]

First time I hear of this too so it makes me suspect it's either some obscure hardware combo that triggers it or its bull****. If it actually existed or still exists, it should be fixed in a BIOS update.

If you want to play it safe, after you've picked what motherboard you want download its MQVL (Memory Qualified Vendor List) manual from manufacturer's website to check which brands and models have been tested with that particular motherboard. Once the rig has been assembled, update the BIOS and reset settings to default. And keep them at defaults unless you know what to change and why.

[Ghostavo]

Yes, DDR3's data rate is twice the numerical value of the I/O bus' frequency, but so is DDR2's and DDR's. I'm not sure why this is a problem.

Your BIOS should however detect JEDEC or XMP's profile in your dims and choose one of them, unless you're manually adjusting things.

[deathspeed]

I agree; I had never heard of this issue before either.  I've build two systems with DDR3 (one Intel and one AMD) and never had any issues like this with either one.  At default settings right out of the box, the BIOS (if working correctly) will detect and use the correct values for the memory using the SPD info stored on the memory module itself.  (http://en.wikipedia.org/wiki/Serial_Presence_Detect) 

Possibly he was talking about changing values while overclocking?  I have not have any experience overclocking DDR3 memory, but maybe there is something there that works differently than earlier iterations of memory.  IIRC, there were concerns early on about overclocking memory on i-series CPUs, but I was thinking that had more to do with running extra voltage thru the memory controller since it was moved from the northbridge to the CPU.

[est1895]

I'm also wondering if I should get an i5 or an i7?  On my system I don't play games, but my brother does.  He's also thinking of upgrading to a new AMD processor when his motherboard fails.  He is the one that plays Freespace SCP.  In fact, when Freespace 2 first came out, it immediately became his most favorite game to play.

[headdie]

seriously if a bug this major had not been detected in the core architecture in 7 years then a lot of industry experts need to be handing in their titles.

In computing, DDR3 SDRAM, an abbreviation for double data rate type three synchronous dynamic random access memory, is a modern type of dynamic random access memory (DRAM) with a high bandwidth ("double data rate") interface, and has been in use since 2007. It is the higher-speed successor to DDR and DDR2 and predecessor to DDR4 synchronous dynamic random access memory (SDRAM) chips. DDR3 SDRAM is neither forward nor backward compatible with any earlier type of random access memory (RAM) because of different signaling voltages, timings, and other factors.

[Dragon]

It's probably a bug with a specific BIOS (most likely), or maybe with a specific type of memory card. Might also be a combination of one and the other. Or perhaps this was a misinterpreted result of a failed attempt at overclocking. Either way, you probably don't have anything to worry about.

[Nuke]

its not an issue, its the way ddr works. it does operations on both the rise and the fall of the clock signal. most of the time you can put it in and not change anything and it will run. performance memory may require tweaks. use memtest86 to verify memory configuration.

[deathspeed]

I'm also wondering if I should get an i5 or an i7?  On my system I don't play games, but my brother does.  He's also thinking of upgrading to a new AMD processor when his motherboard fails.  He is the one that plays Freespace SCP.  In fact, when Freespace 2 first came out, it immediately became his most favorite game to play.

Unless you are using the computer for some intense stuff like graphics rendering, you probably will get much more bang for your buck with an i5.  Even for gaming, despite what many believe, benchmark tests have shown that there are seriously diminishing returns going from an i5-4670 to an i7-4770.  You might check out this article: http://www.tomshardware.com/reviews/gaming-cpu-review-overclock,3106.html