 = Fastra II = 
 
 The Fastra II is a desktop supercomputer designed for tomography . It was built in late 2009 by the ASTRA ( All Scale Tomographic Reconstruction Antwerp ) group of researchers of the IBBT ( Interdisciplinary institute for BroadBand Technology ) VisionLab 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 overheating 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 Joost Batenburg . Unlike other modern supercomputers such as the Cray 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 9800 GX2 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 MSI K9A2 Platinum , which has four such slots . In 2009 , the Asus P6T7 WS Supercomputer 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 tomographic reconstruction . The technique which allows GPUs to perform general @-@ purpose tasks like this outside of gaming , instead of CPUs , is called GPGPU , general @-@ purpose computing on graphics processing units . 
 Overheating caused by the lack of space between the video cards forces researchers using the FASTRA 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 skipped the address space allocation of the GTX 295 video cards . The BIOS @-@ replacement coreboot was not tested . 
 All seven PCI Express x16 slots in the Asus P6T7 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 Lian Li PC @-@ P80 Armorsuit case , which has 10 expansion slots . The motherboard in the Fastra II was at that time the only workstation motherboard that had seven full @-@ sized PCI Express x16 slots . The memory modules were initially six 2 GB modules , 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 initialize . The total amount of GPUs is 13 . The video cards together bring 12 teraflops of computing power . Four of the six GTX 295 video cards have 2 PCBs , while the other two have only 1 PCB . 
 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 Tesla C1060 video card . The benchmarks were performed on the Fastra II , the Fastra I , a 512 @-@ core cluster ( consisting of Opteron CPUs ) , an Nvidia Tesla C1060 workstation card on an Intel Core i7 940 CPU , and on an Intel Core i7 940 CPU 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 Celsius when idle , and at 60 degrees Celsius at full load . 
 
 = = Applications and reception = = 
 
 The operating system is CentOS , a community driven Linux distribution and Red Hat Enterprise Linux clone . The Fastra II received a positive public impression . Techie.com called it the " world 's most powerful desktop @-@ sized supercomputer " , describing it as a computer with " so much power in such a small space . " iTech News Net called it " the Most Powerful Desktop Supercomputer " . 
 Fastra II relies on Nvidia 's Scalable Link Interface ( SLI ) and is therefore limited to the number of GPUs supported by it and also by the vendor respectively the free and open @-@ source device drivers . The Fastra II 's motherboard is designed for workstations , and it is mainly being used in hospitals for medical imaging . 
 It remains to be seen whether another Fastra featuring NVLink , first available with Pascal @-@ based GPUs , will be build . 
 
 