Semiconductor & Computer Engineering
Crystal Well is the codename for the L4 cache, a discrete eDRAM silicon die, which is featured in the high-end Iris Pro-equipped Intel Haswell microprocessors. The eDRAM silicon die is separate from the main Haswell die but is packaged together with it. Crystal Well based processors started shipping in the third quarter of 2013.
Contents
Details
Crystal Well is a true 128MB L4$ which could be utilized by the core itself, not just by the Iris Pro's framebuffer. I.E. L3$ values that gets evicted go into L4$. The L4$ caches serve GPU and CPU memory accesses; memory is partitioned between the two. If the GPU is disabled, such as when a discrete GPU is installed, the L4$ will be used exclusively by the CPU.
Intel has not disclosed many technical specs regarding how the Crystal Well die communicates with the main die. Intel has stated that the cache is capable of delivering 100GB/s bandwidth (50GB/s in each direction).
Note that since Skylake, Intel has changed how the eDRAM works to act as a side cache instead of an L4 cache (see Skylake#eDRAM_architectural_changes for details).
Processors
| Crystal Well Processors | ||||||||
|---|---|---|---|---|---|---|---|---|
| Model | Family | Microarchitecture | Launched | Cores | Threads | Frequency | TDP | Process |
| i5-4570R | Core i5 | Haswell | 4 June 2013 | 4 | 4 | 2,700 MHz 2.7 GHz 2,700,000 kHz | 65 W 65,000 mW 0.0872 hp 0.065 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i5-4670R | Core i5 | Haswell | 4 June 2013 | 4 | 4 | 3,000 MHz 3 GHz 3,000,000 kHz | 65 W 65,000 mW 0.0872 hp 0.065 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4750HQ | Core i7 | Haswell | 2 June 2013 | 4 | 8 | 2,000 MHz 2 GHz 2,000,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4760HQ | Core i7 | Haswell | 14 April 2014 | 4 | 8 | 2,100 MHz 2.1 GHz 2,100,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4770HQ | Core i7 | Haswell | 20 July 2014 | 4 | 8 | 2,200 MHz 2.2 GHz 2,200,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4770R | Core i7 | Haswell | 4 June 2013 | 4 | 8 | 3,200 MHz 3.2 GHz 3,200,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4850EQ | Core i7 | Haswell | 20 February 2014 | 4 | 8 | 1,600 MHz 1.6 GHz 1,600,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4850HQ | Core i7 | Haswell | 4 June 2013 | 4 | 8 | 2,300 MHz 2.3 GHz 2,300,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4860EQ | Core i7 | Haswell | 20 February 2014 | 4 | 8 | 1,800 MHz 1.8 GHz 1,800,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4860HQ | Core i7 | Haswell | 19 January 2014 | 4 | 8 | 2,300 MHz 2.3 GHz 2,300,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4870HQ | Core i7 | Haswell | 20 July 2014 | 4 | 8 | 2,500 MHz 2.5 GHz 2,500,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4950HQ | Core i7 | Haswell | 4 June 2013 | 4 | 8 | 2,400 MHz 2.4 GHz 2,400,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4960HQ | Core i7 | Haswell | 1 September 2013 | 4 | 8 | 2,600 MHz 2.6 GHz 2,600,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| i7-4980HQ | Core i7 | Haswell | 1 September 2014 | 4 | 8 | 2,800 MHz 2.8 GHz 2,800,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
| E3-1284L v3 | Xeon E3 | Haswell | 1 October 2014 | 4 | 8 | 1,800 MHz 1.8 GHz 1,800,000 kHz | 47 W 47,000 mW 0.063 hp 0.047 kW | 22 nm 0.022 μm 2.2e-5 mm |
See also
External links
| instance of | codename + |
| manufacturer | Intel + |
| name | Crystal Well + |