The chipset at the heart of the Gigabyte GA-M720-US3 is the Nvidia nForce 720D. It's a chipset model code that is a bit misleading not least because the final digit is D for Delta rather than a zero. That and the fact the nForce 720D is a single chip and therefore not really a chipset at all.
Although the model code nForce 720D may sound as though it should have a great deal in common with the nForce 720a there are some important differences. For one thing the 720D doesn't have integrated graphics and for another the AM2+ socket on this Gigabyte also supports the latest AM3 Phenom II processors. AM3 uses one pin less than AM2+ so you can fit an AM3 CPU in a Socket AM2+ board but cannot fit an AM2+ CPU in a new AM3 board.
This places the 720D in select company among Nvidia chipsets as there are only three models that support AM3. The nForce 980a SLI supports triple graphics slots, the nForce 740a SLI works with dual graphics cards and this 720D supports a single graphics card.
The Gigabyte GA-M720-US3 supports both AM2+ and AM3 processors which might be seen to pose a problem as the memory controller is in the CPU core rather than the chipset. AM2+ processors support DDR2 while AM3 Phenoms support both DDR2 and DDR3 memory.
Gigabyte has equipped the GA-M720-US3 with four DDR2 slots that support up to 16GB of dual channel 1,200MHz memory which may sound a bit odd. After all, who would want to use a new AM3 CPU with DDR2-1066 memory instead of faster DDR3-1333 which requires less power?
The answer seems to lie with those avid gamers who love AMD processors but who are keen to upgrade from Phenom to Phenom II without dumping the high end DDR2 memory that they have recently bought.
That's the theory but we're not so sure. Fast DDR2 used to cost a fortune but these days you can get 2GB of the fastest 1,200MHz memory for less than £100 and 2GB of 1,150MHz DDR2 only costs £40.
Fast DDR3 can be relatively expensive but Phenom II works perfectly well with DDR3-1,333MHz which is far cheaper than you probably think. Would you believe £40 for 4GB?
This is intriguing as it means that we can see little reason to use DDR2 with Phenom II but it also gives us an opportunity to separate out the elements of the AMD Dragon platform. We know that Phenom II with an AMD 790 chipset and DDR3 memory is an effective combination but what about Phenom II with an Nvidia chipset and DDR2? Here's where we find out.