 = Fastra II = 
 
 The Fastra II is a desktop supercomputer designed for <unk> . It was built in late 2009 by the ASTRA ( All Scale <unk> Reconstruction Antwerp ) group of researchers of the <unk> ( <unk> institute for <unk> Technology ) <unk> at the University of Antwerp and by Belgian computer shop Tones , in collaboration with Asus , a Taiwanese multinational computer product manufacturer , as the successor to the Fastra I ( built in 2008 ) . 
 The Fastra II was determined to be over three times faster than the Fastra I , which in turn was slightly faster than a 512 @-@ core cluster . However , because of the number of GPUs in the computer , the system initially suffered from several issues , like the system refusing to reboot and <unk> due to a lack of space between the video cards . 
 
 = = Development = = 
 
 The computer was built as a researching and demonstration project by the ASTRA group of researchers at the Vision Lab in the University of Antwerp in Belgium , one of the researchers being <unk> <unk> . Unlike other modern <unk> such as the <unk> Jaguar and the IBM Roadrunner , which cost millions of euros , the Fastra II only uses consumer hardware , costing € 6 @,@ 000 in total . 
 The Fastra II 's predecessor , the Fastra I , has 4 dual @-@ GPU GeForce <unk> <unk> video cards , for a total of 8 GPUs . At that time , the ASTRA group needed a motherboard that had four PCI Express x16 slots with double @-@ spacing between each of them . The only such motherboard the ASTRA group could find at that time was the <unk> <unk> Platinum , which has four such slots . In 2009 , the Asus <unk> <unk> <unk> motherboard , which the Fastra II uses , was released , which has seven PCI Express x16 slots . The Fastra II has six faster dual @-@ GPU GeForce GTX 295 video cards , and a single @-@ GPU GeForce GTX 275 , for a total of 13 GPUs . In the Fastra II , the GPUs mainly perform <unk> reconstruction . The technique which allows GPUs to perform general @-@ purpose tasks like this outside of gaming , instead of <unk> , is called <unk> , general @-@ purpose computing on graphics processing units . 
 <unk> caused by the lack of space between the video cards forces researchers using the <unk> II to keep the side panel door open , so that the video cards can get regular air , decreasing the overall temperature inside the case . 
 Due to the number of GPUs in the system , its initial boot was unsuccessful . This was because its motherboard uses a 32 bit BIOS , which only had approximately 3 GB of address space for the video cards . However , Asus managed to provide them a specialized BIOS that entirely <unk> the address space allocation of the GTX 295 video cards . The BIOS @-@ replacement <unk> was not tested . 
 All seven PCI Express x16 slots in the Asus <unk> motherboard were used in the building of the Fastra II computer . However , the video cards in the Fastra II are wide enough to require two such slots each . To solve this issue , the researchers came up with flexible PCI Express cables , and Tones developed a custom cage which allowed the video cards to suspend over the motherboard . 
 
 = = Specifications and benchmarks = = 
 
 Like the Fastra I , the Fastra II uses a <unk> Li PC @-@ <unk> <unk> case , which has 10 expansion slots . The motherboard in the Fastra II was at that time the only <unk> motherboard that had seven full @-@ sized PCI Express x16 slots . The memory <unk> were initially six 2 GB <unk> , but were later upgraded to 4 GB each , for a total of 24 GB . Instead of an eighth dual @-@ GPU video card , the single @-@ GPU GTX 275 is in the computer because , out of all the video cards in the Fastra II , the GTX 275 is the only one the Fastra II 's BIOS can fully <unk> . The total amount of GPUs is 13 . The video cards together bring 12 <unk> of computing power . Four of the six GTX 295 video cards have 2 <unk> , while the other two have only 1 <unk> . 
 According to the benchmarks on its official website , the Fastra II is faster and more power efficient than its competitors , including the Fastra I and the <unk> <unk> video card . The benchmarks were performed on the Fastra II , the Fastra I , a 512 @-@ core cluster ( consisting of <unk> <unk> ) , an <unk> <unk> <unk> <unk> card on an Intel Core <unk> 940 <unk> , and on an Intel Core <unk> 940 <unk> itself . The Fastra II is over three times faster than the Fastra I in CT slice reconstruction speed . Although the Fastra II consumes more power than the Fastra I , it 's nearly 3 times as energy efficient as the Fastra I , and over 300 times as energy efficient as the 512 @-@ core cluster . The video cards run at 37 degrees <unk> when idle , and at 60 degrees <unk> at full load . 
 
 = = Applications and reception = = 
 
 The operating system is <unk> , a community driven Linux distribution and Red <unk> Enterprise Linux clone . The Fastra II received a positive public impression . <unk> called it the " world 's most powerful desktop @-@ sized supercomputer " , describing it as a computer with " so much power in such a small space . " <unk> News Net called it " the Most Powerful Desktop <unk> " . 
 Fastra II relies on <unk> 's <unk> Link <unk> ( <unk> ) and is therefore limited to the number of GPUs supported by it and also by the <unk> respectively the free and open @-@ source device drivers . The Fastra II 's motherboard is designed for <unk> , and it is mainly being used in hospitals for medical imaging . 
 It remains to be seen whether another Fastra featuring <unk> , first available with Pascal @-@ based GPUs , will be build . 
 
 