You can mix-n-match  memory and storage to  custom-build your own ultra compact PC
 Bangalore, July 6 2015: In an earlier era, Dell pioneered  the concept of custom-built PCs  where  you chose a combo of memory, storage, operating system, monitor size -- and they  assembled and shipped the PC to your specification.  Alas, those  days have gone,  to be replaced by a new take-it-or-leave-it  era of limited  choices.  If off -the-shelf  PC options don't please you, there is only one way out: Grab a screw driver and Do It Yourself (DIY).   In the bargain you can build a lean, green and  fanless  compute machine, tailored to your needs  --   and so compact, you can stick it on  the back of your monitor.
Intel  has made this route popular by creating what it calls the Next Unit of Computing or NUC PC  -- a kit-form  ultra compact   PC  which you can configure and assemble. 
Possibly the  biggest name in such compact PCs is the Taiwan-based  Gigabyte, whose  BRIX range of  DIY options is one of the widest in the industry.  They have  just launched 3 models in India -- and I have been tinkering with two of them for a week now.
The BRIX  PC kits come  in a  handy   palm-sized case which  is full fledged PC -- with a choice of  processor, WiFi  antenna,  power cable and   pin-outs   for USB3, HDMI, mini display port, headphone  and ethernet. The bracket to mount the box on the back of a monitor is also provided.  What you need to buy and install is  the  DDR3 memory  -- up to 8GB --and   either  Hard  Disk Drive or Solid State Drive in 2.5 inch size  or one of the new mSATA drives  up to 1 TB.  The display drivers are provided in a CD  but you have to  provide the  operating system. If you load Windows 8.1 now, you can soon upgrade it  for free to Window 10. Otherwise you can opt  for one of the free Linux flavours. I had my  assembled BRIX,  up and ready in 15 minutes. But it takes another hour to load the OS from the installation CD.
Once you remove  four screws and remove the cover, it is fairly easy to mount the   HDD, SSD or mSATA  disk drive  and insert the memory modules into one or both slots provided.  You will need to attach an external  DVD/CD drive to the USB port to load the  OS of your choice.... and  find a suitable display. Extremely light HD displays can be had for  less than Rs 5000. By my rough calculation,  a 500 GB SSD drive and 4 GB of memory will set you back around Rs 15,000 and the Windows 8 OS will  cost around Rs 7000.
The entry level  GB-BXBT-2807  BRIX costs Rs 10,500, while the GB-BXi3H-5010  and  GB-BXi5H-5200 are priced  Rs 23,000 and Rs 32,000 respectively. The difference is in the processor  which ranges from basic Celeron to  Intel  Core 5  with  graphics.  Even the basic  model supports  full HD displays while the  two pricier models  support 4K- UHD. Indeed, there are hardly any  ready made PCs yet, that are 4K ready -- and if you own a 4K TV set,  the BRIX might be the only practical  way to  feed your   home theatre with UHD content.   I think the true strength of  this DIY PC might be as a home multimedia hub: it  can drive two displays at the same time.
Spec for spec,  the Gigabyte PC kits may end up costing more for a complete system than  many off -the- shelf PCs. But  for the little more you pay, you get something tailored to your needs. The envious  taalis you earn when you casually tell your friends , "I built  it myself" -- well, that's  a bonus! --Anand  Parthasarathy