Data General Corp launched its non-uniform memory architecture (NUMA) servers with the bold claim that they are twice as fast and half the price of the main opposition. And in another dig at rivals Sequent Computer Systems Inc, it said a four-processor ccNUMA system running Windows NT is likely to be announced in a few weeks. The battle between vendors has become as much about who can integrate Windows NT first as about the speed of their products and Sequent said last month (CI 3,168) that it planned to launch a server that would run both Windows NT applications alongside Unix in a few months. Data General’s Aviion 2000 can accommodate up to eight four-way standard high volume Pentium Pro boards linked with the Scalable Coherent Interconnect technology the company licensed from Dolphin Interconnect Solutions Inc. Each board comes with up to 512Kb cache, 4Gb RAM and 12 slots and can be connected with up to 128Mb distributed cache memory and 100Tb Clariion FC5000 Fibre Channel RAID disk storage. How is it likely to measure up against Sequent’s NUMA-Q machines? Waiting for memory What slows NUMA machines down is latency – the time during which a processor has to wait for memory. Vendors try and keep the latency to a minimum by using caches. So the time difference between local cache and remote memory access is a good indication of the overall performance of the machine. Sequent has said that it takes between 180 and 300 nanoseconds to access local cache and 3 microseconds to access remote memory. That’s a differential of around 10 times. Data General’s Linda Mentzer, vice-president of the Unix Business, said that their differential was only around four times. It does admit that decision support applications scaled up in a more linear fashion than online transaction processing applications which explains why decision support benchmarks will be revealed shortly and those for transaction processing some time later. AV 2000 prices start at $70,000 for a quad with 512Mb RAM. while a 32-processor configuration is $690,000. Data General says a clustered configuration currently supports two 32-way systems; four node clustering will be supported from the year-end. The disappointment for users is that AV 2000s currently run a version of the company’s DG/UX Unix configured to support ccNUMA. Santa Cruz Operation Inc’s Gemini Unix for ccNUMA won’t be delivered until the end of the year, though they’d been promised delivery around now. Data General also announced its Clariion FC5000 Fibre Channel RAID subsystem plus a SCSI-to-fibre channel adapter for use with the SCSI-based Series 3000 arrays. Third parties such as Hewlett-Packard Co and Silicon Graphics Inc are making Data General’s Fiber Channel products under license.