The DIMMS Up Close
From a physical standpoint, the Corsair CMX1024-3500LL PRO DIMMs are somewhat unique when compared to competing products. Aside from Corsair's other "PRO" branded products, no other memory modules feature activity LEDs like these modules do. Crucial has a similar product on the market, but they don't quite look like Corsair's. The 18 LEDs on Corsair's "Pro" memory kits blink rapidly to show the level of memory activity, much like the sound meters found on some audio equipment. Unless you have a windowed case the activity LEDs will go unseen though, so make sure to feature them prominently if a set of these DIMMs is in your future. The activity LEDs are definitely attention grabbing.
Aside from the activity LEDs though, there isn't much to talk about besides the physical size of these modules. As you can see, the CMX1024-3500LL PROs are quite a bit taller than most other DDR memory modules. This won't be an issue in most circumstances, but these sticks may not fit into some small form factor systems that have limited clearance above the DIMM slots. So, make sure you've got the room before you make a purchase. The memory chips that populate the PCBs are covered with large, finned heatsinks clearly labeled "XMS". The small fins add a significant amount of surface area, when compared to the more commonly used flat heat spreaders, and should be more than capable of keeping the RAM cool provided your case is well ventilated. Corsair has actually commented recently on the effectiveness of these heatspreaders relative to some new products from their competition. You can see some of Corsair's comments in this post on our main page from a few days back.