4GB FULLY BUFFERED PC2-5300 DDR2 ECC (FB-DIMM) (2 X 2GB) FOR APPLE KIT by Arch Memory

This memory was easy to install and was recognized by both my Mac OS (Lion) and Windows 7. Note: you will need Windows 7 64 Bit to access more than 2 or 3 GB of RAM in a Mac Pro (or just about any computer) because the video card memory maping will take some of the usable RAM space. This memory is MUCH less expensive than what you will get from Apple and works perfectly. I removed the 4 512BM sticks and simply put in 4 2GB Modules, now I've got 8GB of usable RAM.What will going from 2GB to 8GB get you on your Mac Pro (or any computer really)? When running many apps, the system will simply run faster. Everything from web browsing to intensive media editing will run faster. Really, this is the least expensive way to improve performance in your computer. If you have 2GB or less, buck up kiddo and get more RAM.

Lets make it short and easy:Computer: Mac Pro 2008 - Intel Xeon Quad CorePros: Works perfectly, and installation is a snap.Cons: You can't use it with any other RAM (from Crucial or any other).I have 8 Slots for RAM which means I can only buy 4 packs of this :(, i really wish it was 1x4GB that way i could boost my computer to 32GBs instead of 16GB.Shipping: Arrived perfectly on timeI will diff. Recommend this to any MAC PRO User :)Update (August 6, 2012): The RAM is working perfectly, but i just realized that using 2GB modules can only give me 16GB on a MAC PRO 2008. I wish these were available in 1x4GB or 1x8GB that way i could've added A LOT more RAM to my Mac Pro :(

I was very happy with the price of these chips. But once the chips start to heat up, they can get very loud. At first I thought my computer was going to just blow up because my computer fan started to spin very fast. In the end, it is a very good bargain. I'll buy more soon. Just turn your music up so you don't hear the roar.

I have one of the original Mac Pros with the twin dual core Xeon 2.66GHz processors and it shipped with 4gb of RAM (2 x 2GB). I added another 4GB from Crucial about 2 years ago and really needed 16GB.This RAM is amazing for the price. I installed 8GB of this for under $90 where the Apple memory would have required me to sell a Kidney or my Spleen (if I had a Spleen, but I don't so that wouldn't work and I kind of need that Kidney as a result).So the RAM works perfectly and the only thing that has happened is that my machine is running a lot better as it has WAY more RAM overhead for Video Editing and also running Virtual Machines in Fusion.I have not noticed any appreciable increase in heat, fan speed, or anything else that would warrant writing home about.Love this memory and would buy more if I needed it!

I bought this memory for my Apple Mac Pro 1.1 which came with 2gb of factory memory installed (taking up 4 of the 8 available memory slots). I had already upgraded the 2 gb Apple memory with an additional 4 gb of Crucial branded memory making 6 gb of installed memory, and now, in order to try to extend the useful life of my beloved Mac Pro, I decided to replace the original Apple memory DIMMs with 4 x 2 gb of memory from Komputerbay plus another 4 gb which would bring the total complement of memory to 16 gb (6 x 2 gb KomputerBay FB-DIMMs plus the Crucial 2 x 2 gb DIMMs).I read the reviews about the fan speed increase, but thought I would take my chances as the great price is hard to ignore. Well, I installed the new memory and two of the new FB-DIMMs were not recognized by my Mac Pro, so I removed the two faulty DIMMs and replaced them with two of the 4 Nanya brand DIMMs that came with my computer. The funny thing is that the other reviewers were right. The fans really roared, but only for a few days. Now my computer is running great with only a marginal increase in the fans speed. I really don't know what that is all about. According to the TemperatureMonitor.app, which I downloaded from Cnet.com, the memory bank temperatures are all under 97°F, but the memory module temperatures vary quite a bit.Memory ModuleA1 - 136°F,A2 - 142°F,A3 - 136°F,A4 - 122°F,B1 - 180°F,B2 - 147°F,B3 - 111°F,B4 - 115°F. Modules B3 and B4 are the original 256mb DIMMs and they can be expected to run cooler as they are not as dense as the 2 gb DIMMs. Module B1's temperature is clearly the outlier. It's possible that B1 does not have the benefit of the best airflow from the fans.After a couple of days of very loud fan noise, it seems the temperatures are about the same, but the fan noise has diminished to what was more or less normal before the memory upgrade. I am returning the faulty set of 2, 2 gb DIMMs and will buy a replacement set to again make up a full complement of 16 gb. So to summarize my rating, I am very happy with the memory upgrade, and I will buy them again. The return of the bad set is a small hassle but that is well worth it if the credit/replacement issue is resolved.Update: The credit issue was not a problem. My money was refunded promptly for the defective module, and I repurchased another set. My computer runs fine now, and there is no fan noise beyond what is normal. I'm very satisfied!