Both phones have a block form factor with giant touchscreens. Optimus Black is quiet slim with only 9.2mm of thickness, it also weighs just 109g. HTC desire is not as slim as Optimus Black but definitely has a more catchy and stylish design. It is 11.2mm thick and weighs 130g which is just about good. Even though Optimus Black is lighter and slimmer, it is wider and longer than Desire S. With a better design HTC Desire S just about steels the looks show.
HTC Desire S features the S LCD capacitive touchscreen panel while Optimus black has the more latest IPS LCD capacitive touchscreen which is brighter and more vibrant than the S LCD of Desire S. Optimus Black also has 4 inch of screen size which gets the better of 3.7 inch touchscreen of Desire S, making it a clear winner on the display front.
Processor and OS:
HTC Desire S is powered by 1 GHz processor housed in a Ti-OMAP chipset and runs the latest Android 2.3(Gingerbread). Optimus Black also features 1Ghz processor with Adreno 205GPU. It runs Android 2.2 which is upgradeable to the latest Android2.3. There is not a lot of difference in processing powers and OS of these smart phones, so very much a tie here.
Both phones feature 5MP auto focus primary camera with LED flash and resolution of 2592 x 1944 pixels, both smart phone have the ability to record HD 720p videos at 30fps but LG with its 2MP front camera compared to the secondary VGA camera in HTC desire just takes the lead.
Optimus Black comes with 2GB of internal memory and 512MB of RAM, HTC desire has 1.1GB of internal storage and 768MB of RAM. Both phone support the sd micro card up to 32GB to extend the storage capacity.