Intel's plans for the next four years were leaked a bit prematurely before its Intel Developers Forum (IDF) this month. Now with the IDF in full swing, Intel is releasing many more interesting details on the upcoming processor that is on top of its list -- Nehalem.
Formally known as the Intel Core i7, Nehalem features eight logical cores, the return of HyperThreading, on die memory support, QuickPath, and more. It will launch later in 2008.
One interesting revelation which Intel left off with was that it would probably release its notebook processors at almost the same time as its desktop variants, unlike with its Penryn processors. It expects many of the power-saving technologies found in Nehalem to be very useful in preserving laptop battery life.
The first intriguing technical detail of Nehalem according to Techgage is the new "Turbo Mode". Similar to the Turbo button of 386 days of yore, the turbo functionality will up the power to the CPU. Overall performance will be reduced in Nehalem to save power. For example, three cores of a four-core Nehalem processor could be turned off while a system is idle. More power can be transferred to that single core as well when performing simple operations that don’t require four cores blazing away.
However, if more CPU power is needed, power can be distributed to the remaining cores. Turbo Mode can be turned off in the BIOS and does not replace traditional overclocking.
Also discussed was Intel's new on-chip memory controller. It uses three channels in an unusual approach. The approach is apparently paying off as memory bandwidth with its QuickPath Interface (QPI) is up to 25.6 GB/s, almost 3.5x the performance of current gen memory. Unfortunately, Intel refused to divulge latency information, so the memory picture is still incomplete, though it’s looking bright on the bandwidth side of things.
As Nehalem samples have been show capable of working with even the highest end DDR3, DDR3-2000, many are now beginning to wonder whether such high speeds will even be necessary given the massive bandwidth. Some are speculating that Nehalem's impressive memory performance will spell death for the high end memory market, already hurt by sinking prices.
It’s hard to say whether this will happen as increasingly there will be scenarios that call for massive memory use. Intel is making big claims about its bandwidth, however. According to Intel one stick of DDR3 on and Intel X58 motherboard with a Nehalem nearly equals the bandwidth of a dual-channel DDR3 configuration with a Penryn processor. Nonetheless, memory manufacturers are planning to release 3 GB DDR3 kits to coincide with Nehalem for 32-bit OS's and 6 GB and 12 GB kits for 64-bit OS's.
While IDF attendees were sworn to secrecy on performance specifics, they did say that the overall performance shows good gains, similar to the Penryn. They say that HyperThreading features few surprises and aside from some minor improvements is virtually identical to that used in the Pentium 4.
In conclusion, there are a few new juicy details on Nehalem, but in the end even more questions. Fortunately answers will be coming in a few short months. With AMD's Shanghai set to compete with Nehalem, perhaps the most interesting question of all is when will Nehalem's competitor materialize.
quote: More power can be transferred to that single core as well when performing simple operations that don’t require four cores blazing away.