Saturday, November 14, 2009

Google proposes new transfer protocol for the web

Addressing the inherent limitations of HTTP protocol, Google researchers are proposing a new transfer protocol. SPDY uses a single SSL-encrypted session between a browser and a client, and then compresses all the request/response overhead. The requests, responses, and data are all put into frames that are multiplexed over the one connection. This makes it possible to send a higher-priority small file without waiting for the transfer of a large file that's already in progress to terminate. Compressing the requests is helpful in typical ADSL/cable setups, where uplink speed is limited. For good measure, unnecessary and duplicated headers in requests and responses are done away with. SPDY also includes real server push and a "server hint" feature.

Long established protocols like HTTP are resistant to change, but the ideas proposed are a good way forward in terms of making the web more secure and faster for everyone.

Source: Ars

Friday, November 13, 2009

AMD "Bulldozer" architecture to sport 8 cores and 128 bit floating point unit



Advanced Micro Devices this week disclosed the first details about its next-generation Bulldozer processor that is due in 2011. Although specifications of the chip seem to be rather promising at this point of time, in about one and a half years from now the central processing unit (CPU) may face a too strong rival and repeat the history of its predecessors.

Based on the information provided by AMD during its annual Analyst Day in November, the first Bulldozer chip code-named Zambezi (which belongs to Orochi family, according to the firm) will feature eight x86 processing engines with multithreading technology, two 128-bit FMAC floating point units, shared L2 cache, shared L3 cache as well as integrated memory controller. AMD also states that the new CPU will feature “extensive new power management innovations”.

The implementation of 128-bit FMAC is quite logical: AMD’s SSE5 set of extensions do feature 128-bit multimedia instructions as well as 128-bit three-operant instructions. In fact, there is a trend of increasing of precision of floating point instructions, as we can observe from the last decade.

What is important to note is that Intel Corp.’s forthcoming Sandy Bridge processor features Advanced Vector Extensions (AVX), which support 256-bit FP operations, something very progressive. Both AMD and Intel have already released documentation regarding AVX and SSE5 for developers, but Intel managed to unleash a new compiler supporting AVX in June ’09, whereas AMD has not managed to roll-out an SSE5-supporting tool. As a result, the vast majority of developers are already capable of creating AVX-capable software; however, almost no designers can make SSE5-capable programs at the moment.

Nevertheless, based on the diagram that AMD demonstrated, the company intends to dramatically improve multithreading performance of its CPUs: two INT schedulers, an FP scheduler and separate data caches for each of four cores should do the job very well.

AMD has not released any data regarding performance of Bulldozer chip, unfortunately, but since the chip designer positions the unit as a solution for desktop and server solutions in 2011, it does expect this 32nm SOI with high-k metal gate power-house to be a high-performer.