Kingston's 128GB DDR3 Reviewed: Sometimes Control is Just Good

The net is full of articles talking about how this or that technology company is controlling their software, hardware, IP (Intellectual Property) or some other item that they want to complain about. You also cannot run a search on net-neutrality, DMCA, MPAA, RIAA, The Pirate Bay or, of course Apple without hearing about how medieval and out dated their concepts of fair usage are. I have talked about this kind of corporate control for years as well. It is oppressive, stifles the market and hurts the consumer. However, there is one type of control that is good for the consumer.


16 8GB DDR3-1066 memory modules i.e. 128GB of memory, just about the maximum you can put in an dual-socket AMD Opteron 6100 Series system

This is the type of control that Kingston is holding over their ValueRAM Server Premier memory. What Kingston has done is take their already great server memory and add an extra level of quality control to ensure maximum performance and stability. They have done this by controlling every part that goes into this product right down to the revision of chip die. Let’s take a quick look at how this works and what it means to the consumer and enterprise.

There is a BOM!
BOM (Bill of Materials) references every part that goes into building a specific part. If you were building a Video Card your BOM would include each component right down to the resistors and PCB used in the product. Normally a BOM is only component specific. A BOM might say six layer PCB (Printed Circuit Board) or 100 .1 Ohm resistors but it would not go so far as to state the Lot Number, revision number or anything else. If you take a typical stick of memory you might notice that the chips do not always match for lot number. The same can be said for building any component. Companies do not have time to match lot numbers as they build product. In fact most do not even try. They take parts from stock as they are put in. Oddly enough, it is only by chance that you get parts from the same Lot. This happens because when Lots are manufacturer they are packaged for shipment around the same time so these components end up going to the same places. As Lots are usually in the hundreds of thousands there is a good chance that you may get the same Lot parts in a single product.

To a consumer buying a dual or triple channel kit of memory you this means that your chance of getting parts with different Lot components it fairly slim. To the Enterprise customer who buys 16, 32, 48, or more sticks of memory in a single purchase the likelihood goes up dramatically.

It's our Lot in life...
So why are different Lots bad? To put it simply a Lot is a group of components or products that were all manufactured the same way and at the same time. This is often referred to as a production run. Once that run is complete there can be small changes to the way the next group of pieces are manufactured. This is normal and happens over the manufacturing life of a specific part. This is why you may hear about a recall of a product with serial numbers ending in “XXYYY” those numbers identify the Lot. Now, as we mentioned, there is a normal shifting in a product over its manufacturing lifecycle. This shifting is very gradual and is normally not noticeable to the consumer as parts from adjacent Lots (Lots that were made before and/or after a specific Lot) are usually so close that it makes no difference in performance or stability. Where things begin to go south is when there are massive differences in the Lot numbers (say 10 or more). Then things can get a little weird.

When Tolerance attacks
Now that we have briefly (very briefly) told you about BOMs and Lots let's talk about why they are important and how they play into what Kingston is doing. Every part has a certain specification (spec) and this spec has a tolerance that is has to meet or it gets tossed into the bin. A tolerance is measured as a plus or minus to the designed spec. For example; if I design a battery and I say it puts out 3.3 Volts that is my Design Spec.

Now during manufacturing and testing we find out that sometimes (depending on the manufacturing run) they put out 3.35Volts or 3.26Volts (and still work) their tolerance is +/- .04. This lets you know that anything in that range is acceptable. In electronic and computer components you have the same tolerances. In a single Lot you have that tolerance built-in and it forms the standard deviation for manufacture. During the manufacturing lifecycle of a product this deviation can drift one way or the other. Again adjacent lots are usually so close you would never know but Lots that are significantly separated may have a deviation that are just too far to work together. You end up with the same parts in terms of design but the tolerances are so diametric they just won’t work together. 

In another example let’s say a voltage regulator is designed to 3.3V the tolerance is +/- .05. In lot A the regulators are all at 3.31 in lot B they are 3.29 when you put them together they are only .02 off so no harm done there. Now lot C might be at 3.28 and lot D at 3.27 this means that if you put regulators from Lot A and Lot D together you have a difference of .04 we are pushing the tolerance of these parts when they are put together.  Once you are out of tolerance for parts in a grouping you have potential for failure.