While both the EP45-DS3L and EP45T-DS3R are based around Intel's P45 Chipset, these two Gigabyte motherboards are in fact very different. The EP45-DS3L represents the lite version of the EP45T-DS3R. Instead of using the ICH10R Southbridge, the EP45-DS3L uses the ICH10 and it only has one Gigabit Ethernet Controller, one PCI Express x16 slot, DDR2 system memory, and a slimmer set of features in general. When it comes to the real-world Linux performance though, both motherboards had performed about the same and almost equivalent to the ASRock P45R2000-WiFi as well. With that said though, there is a bit of a price difference between the Gigabyte EP45-DS3L and the Gigabyte EP45T-DS3R. The lower-end motherboard goes for just $110 USD while the high-end one will set you back $175. Is this $65 premium (or about 60%) justifiable? It depends upon the requirements for the system. If you are just looking to build a PC for casual gaming or Linux desktop use, the lower-cost EP45-DS3L will easily get you by and you will be saving a fair amount of money. However, if you are looking to build a PC with all of the bells and whistles and upgrade capabilities for the future, the Gigabyte EP45T-DS3R is the motherboard worth pursuing.
For the Linux users, you will need to be using a recent kernel (2.6.26+) in order for the SATA disk controller to be detected, which means for some users you'll need to use the latest development build of your favorite distribution. If this concerns you, wait for a few months until the distribution you are after has a new version out or take a look at an Intel X48 motherboard with the ICH9/ICH9R Southbridge. Both Gigabyte motherboards are competitively priced for their feature sets and both offered great overclocking capabilities where we had no problems pushing the Core 2 Duo 8400 to 4GHz. Even after testing these motherboards for a few weeks now, they continue to churn along great using the latest Ubuntu 8.10 Alpha builds. We would highly recommend either one of these motherboards for their features, Linux compatibility (including LM_Sensors), board design, and performance.
For pricing and additional reviews on the Gigabyte P45 motherboards as well as other Intel motherboards, check out TestFreaks.com.