Feb 22 2012 Update: $207.99 USD after promo code, ends midnight eastern time tonight! Here's the purchase link:
Here's my DIMM drama. An intriguing tale of a month or so of oh no, followed by 32GB of sweet oh yeah!
I was going for longevity, and commonality, for parts swapping, when components inevitably begin to fail down the road. Given plans to build another system in my house, I standardized on the ASRock Fatal1ty Z68 Professional Gen3. I also wanted PCI pass through capability, and many SATA3/6Gbps ports, all for a reasonable price.
Just as my lab-in-a-box was pretty much complete and my use of simultaneously running VMs went up past 8, the prices of getting 4 of those 8GB DIMMs began to look reasonable. Prices fell from upwards of $600 in 2011, to downwards of $300 in 2012. Glad I waited.
So I headed back to the ASRock Fatal1ty Z68 Professional Gen3 Memory Compatibility chart here:
and suddenly had this sinking feeling, when it became apparent that not only was there only one suitable 8GB DIMM listed, the A-DATA 8GB AXDU1333GW8G9, but it was also not in stock anywhere. Well, besides Germany, for like $600 for 32GB on eBay.
So the hunt was on, finding evidence of some other 8GB DIMMs compatible with this motherboard. I had recently had lock-up issues on gZilla when going to 2 560 Ti GPUs (SLI) and 4 DIMMs, using Corsair memory that wasn't on this compatibility list (leftover from previous motherboard tests). In no way was that Corsair's fault, of course.
This time around, I really wanted something in writing from ASRock support, stating what would work. Even if that item hadn't made it to their compatibility charts.
I got that answer from ASRock support on January 25, 2012:
G.SKILL [ RipjawsX ] F3-10666CL9Q-32GBXL (8Gx4)
Note the G.Skill site even has it's own "Qualified Motherboards List," which includes my motherboard, phew! And the 32GB kit is sold with lifetime warrantee, in a prematched 4 pack (see photo below, shows front and back views of package).
So I saved my pennies, and got in touch with a TinkerTry.com visitor who was seeking 32GB as well. This Canadian pulled the trigger first on the same G.SKILL kit, installed them, and kindly let me know that the 32GB worked fine.
Placed my order this week, $269.99 even got me overnight delivery from newegg.com's NJ warehouse:
G.Skill Ripjaws X Series 32GB (4 x 8GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666)
Desktop Memory Model F3-10666CL9Q-32GBXL
Installed them, set the BIOS to automatically detect CAS Latency 9-9-9-24-2N, at 1333. Booted the Memtest86 CD, and after 1 hr of passing the tests (see video below), I went ahead and let ESXi 5.0 boot, no problems noticed, TinkerTry.com/vzilla build list updated, end of story!