March 1999 SDRAM Comparison

Another issue that never came into question in the September comparison was the price of the individual modules, simply because there weren't any "novelty" entries into the comparison. However as previously mentioned, times have changed, and this time around AnandTech received some SDRAM samples that were a bit out of the reach of the average consumer, but included in the comparison nonetheless.

The price to stability ratio is a consideration that we must all make unless you happen to be in the rare position where cost isn't a factor at all. At the same time, you need to shrug any teachings that may have told you that a higher price means a product that requires higher quality material to construct and is therefore superior. Case in point would be the controversial Samsung G8 vs GH chips that have been floating around the storefronts of many vendors. While the G8 chips are rated at a higher clock speed, their actual stability is lower than that of the GH chips at higher Front Side Bus (FSB) frequencies, however the G8 modules are priced noticeably higher than their superior GH counterparts by some vendors. Why on Earth would something of lesser quality be priced higher than a better overall solution?

The driving force behind this unique situation happens to be the classic price war scenario, where one vendor sets the price on a particular product, and in order to compete with that vendor, another vendor selling an identical part will set a similar price on that product, even going to such extremes as making the price difference a mere dollar. In the end, the consumer is the one who benefits, however the mentality of most is that the more expensive solution is the better solution, when in reality, the more expensive solution was the result of a price war and not in fact the better solution. So lesson number two is to disregard everything you may have learned about price differences and remember that more expensive doesn't necessarily mean better.

System RAM is accessed in rows and columns by other components in your system, if you look at 64MB of RAM as a table split into a number of cells then it becomes easier to understand how RAM is accessed. Although the actual process isn't as simple as opening up Excel and searching through a few data cells, it is the fundamental idea behind accessing RAM. Both of these strobes are signals that your CPU or other device (like the processor on your video card) sends to your RAM. They tell a circuit in your RAM module that an address line is correct. In the case of RAS, that the row is correct, or in the case of CAS, that the column is correct. The speed at which you access a single row of RAM is defined as the Row Access Strobe Latency, or RAS Latency; and as you may be able to guess, the speed at which you access a single column of RAM is defined as the Column Access Strobe Latency, or CAS Latency.

CAS Latency ratings vary from chip to chip, and also varies depending on the bus speed used with the modules. While a chip may carry a CAS rating of 2 (lower is better) at 66MHz [bus speed] the rating on the chip may rise to 3 if used at 100MHz. Meaning that if you were to set the CAS Latency via your BIOS Setup to a value of 2, then upped the FSB frequency to 100MHz you would be going beyond the specification of the chips themselves and you could start to experience instability. The ideal, yet realistic, goal is to get a module that is rated at CAS 2 for 100MHz and CAS 3 for anything higher than that, be sure to get the facts straight from your vendor before placing an order as this will ultimately dictate how stable your RAM will operate at higher bus speeds.