Intel’s Haswell processors likely to include L4 cache
Intel’s future Haswell architecture, which will be the successor to Ivy Bridge, is very likely to include L4 cache that will be used for sharing data between the integrated GPU core and the CPU core. The result – vastly improved 3D performance.
As of now this interesting information has not been confirmed or rebuffed by Intel but there has been evidence that suggests that one day we will see processors with L4 cache. In addition the evidence also suggests Haswell will offer an integrated GPU that will be two to three times faster than the fastest 3D Ivy Bridge can offer.
The biggest change however will be the addition of integrated L4 cache memory. This addition, if it ever occurs, will continue the trend of offering more and more on-chip cache in desktop processors that started with the introduction of the 80486 processor back in 1989. In the early 2000s the L2 cache memory, until then built into the computer motherboard, migrated directly into the CPU and in 2003 Intel also integrated L3 cache in certain limited and very expensive high-end Pentium 4 processors. Today it is common to have L3 cache in your system’s processor. As to the L4 cache, nowadays it can be found only in expensive chips aimed at the high-performance computing market.
The L4 cache in Haswell will not serve the CPU cores directly – instead it will be there to meet more or less the needs of the integrated (and supposedly much faster) GPU. Intel believes that increased coherency between the graphics and central processing infrastructure on chips is the way forward and the increased coherency will be created best by L4 cache.
For the average user, this would mean vastly improved graphical capabilities, which may cause the death of low- and potentially even mid-range dedicated graphics cards. For the server room it means the ability to execute instructions on either the CPU or the GPU independent of where the data is stored, eliminating one of the biggest bottlenecks in general purpose GPU (GPGPU) programming – moving data.
Intel did not comment on the story. Haswell is expected sometime in 2013 or 2014.