PC133 CAS2 SDRAM Competition Corsair Vrs. Mushkin

PC133 CAS2 SDRAM Module Competition
Corsair Vrs. Mushkin

By Dave Altavilla - September 19, 2000

 
It makes sense to break things down a little further for you at this point.  Let's have a closer look at the chip level components on these two modules and what kind of specifications they bear.

First let's look at Mushkin...

These are 7ns. 8MX8 Synch. SDRAM chips.  Here is a table of their timing characteristics courtesy of Mosel Vitelic Semiconductor.

Here we see a Clock To Access Time of 5.5ns. and support for CAS Latency of 2 performance up to 143MHz.  Remember, these are chip level numbers.  When there are several of these parts on a module, other timing issues come into play like chip to chip timing, so specifications at the module level may be different.

Now let's look at Corsair's module with Micron on board...

Similar to the Mosel chips, these are also 7ns. 8MX8 SDRAM rated at 7ns.  Here are their timing tables courtesy of Micron Semiconductor.

Our module has the "-7E" parts on it, as you can see in the picture above.  Here we see slightly less aggressive timings with a CAS2 Allowable Operating Frequency of 133MHz.  Now, with this in mind, "specsmanship" between Semiconductor Manufacturers is a delicate game.  Micron may just be a little more conservative in the way they characterize their parts.  Still, looking at the specs, it seems as though the Mosel devices can handle a CAS Latency setting of 2 up to 143MHz. and the Micron only up to 133MHz.

Benchmarks / Comparison Between CAS2 and CAS3 Settings So, what's the big deal?

Here is a quick look at what sort of performance gain CAS2 versus CAS3 settings can produce.

H.H. Test System The latest and greatest LiteOn Mid Tower ATX Case w/ 300W PS, Pentium III 933EB, MSI MS6337 i815 Motherboard and nVidia GeForce2 Ultra, 128MB of PC133 True CAS2 SDRAM from Corsair and Mushkin (thanks Outside Loop), IBM 15Gig 7200 RPM ATA100 Hard Drive (thanks again Outside Loop), Kenwood 72X CDROM, Win 98SE, DirectX 7.0a

First, we'll get a 10,000 foot view of performance from SiSoft's Sandra Memory benchmarks.

The first thing to note is that when all things are equal, bus speed and CAS Latency settings that is, both modules perform identically.  The next thing to note in the CAS3 scores (taken only on the Corsair sticks) is there is a fair amount of bandwidth lost.  Even at a 160MHz. FSB, the CAS3 timings can't keep up with CAS2.

Now, how does this affect real world performance?  That's what we have in store next...

More CAS2 Performance, The BIG Stability Test and Ratings