The Viper Radeon HD 3650 1GB is a small, very compact graphics card, measuring just 17.5cm long and taking up a single expansion slot.
Diamond has not gone with the standard heatsink design, rather they have installed their own cooler. This upgraded cooler is not really much of an upgrade. In fact, it could be seen as being a bit of a downgrade, as the cooler looks much more like the one found on the Radeon HD 3450. Thankfully this will still cater for the memory chips on the front side of the graphics card.
Diamond has countered the slightly smaller heatsink with a louder and faster fan. The problem with this is that for such a small card, the Viper Radeon HD 3650 makes quite a bit of noise. This came as unexpected, and while the noise generated by the fan is hardly extreme, it is not going to make it desirable for those building a HTPC system.
It should be noted that the fan speed is not automatically adjusted depending on the graphics card load or temperature, and therefore spins at maximum speed even when in 2D applications.
The card ships with the standard core and memory frequencies (725MHz/1000MHz) using 1024MB of GDDR2 memory. It shall be interesting to see if the additional 512MB of memory has any impact on the performance of this graphics card. Diamond has used Hynix HY5PS121621C FP-2 memory chips which are designed to operate at 1000MHz DDR.
As noted before, this is a PCI Express 2.0 x16 card, built around the ATI RV635 Pro graphics chip, using a 55nm design process.
The Radeon HD 3650 generates just 16.0GB/s of memory bandwidth using a 128-bit memory bus, which is considerably less than that of the old GeForce 7600 GT. The card supports dual-link DVI via two DVI ports, while also offering support for TV-Out and Multi-view. Additionally it is nice to see that Diamond has included a HDMI port with multi-channel 5.1 surround audio support. However be aware that VIVO support is not included (Video-In/Video-Out).