Lines Matching +full:number +full:- +full:of +full:- +full:wires
5 ----------------------------------------
7 There are several things to be aware of that aren't at all obvious, like
8 *sockets, *socket sets*, *banks*, *rows*, *chip-select rows*, *channels*,
11 These are some of the many terms that are thrown about that don't always
12 mean what people think they mean (Inconceivable!). In the interest of
19 output 4 and 8 bits each (x4, x8). Grouping several of these in parallel
20 provides the number of bits that the memory controller expects:
21 typically 72 bits, in order to provide 64 bits + 8 bits of ECC data.
27 gets replaced, in the case of excessive errors. Most often it is also
37 A memory controller channel, responsible to communicate with a group of
43 It is typically the highest hierarchy on a Fully-Buffered DIMM memory
49 is calculated using two DIMMs instead of one. Due to that, it is capable
50 of correcting more errors than on single mode.
52 * Single-channel
55 only. E. g. if the data is 64 bits-wide, the data flows to the CPU using
57 memories. FB-DIMM and RAMBUS use a different concept for channel, so
60 * Double-channel
63 dimms, accessed at the same time. E. g. if the DIMM is 64 bits-wide (72
67 * Chip-select row
69 This is the name of the DRAM signal used to select the DRAM ranks to be
70 accessed. Common chip-select rows for single channel are 64 bits, for
75 * Single-Ranked stick
77 A Single-ranked stick has 1 chip-select row of memory. Motherboards
78 commonly drive two chip-select pins to a memory stick. A single-ranked
79 stick, will occupy only one of those rows. The other will be unused.
83 * Double-Ranked stick
85 A double-ranked stick has two chip-select rows which access different
86 sets of memory devices. The two rows cannot be accessed concurrently.
88 * Double-sided stick
90 **DEPRECATED TERM**, see :ref:`Double-Ranked stick <doubleranked>`.
92 A double-sided stick has two chip-select rows which access different sets
93 of memory devices. The two rows cannot be accessed concurrently.
94 "Double-sided" is irrespective of the memory devices being mounted on
95 both sides of the memory stick.
99 All of the memory sticks that are required for a single memory access or
100 all of the memory sticks spanned by a chip-select row. A single socket
101 set has two chip-select rows and if double-sided sticks are used these
102 will occupy those chip-select rows.
107 between chip-select rows and socket sets.
111 HBM is a new memory type with low power consumption and ultra-wide
113 interconnected by microscopic wires called "through-silicon vias," or
116 Several stacks of HBM chips connect to the CPU or GPU through an ultra-fast
118 are nearly indistinguishable from on-chip integrated RAM.
121 ------------------
123 Most of the EDAC core is focused on doing Memory Controller error detection.
128 .. kernel-doc:: include/linux/edac.h
130 .. kernel-doc:: drivers/edac/edac_mc.h
133 ---------------
139 .. kernel-doc:: drivers/edac/edac_pci.h
142 -----------
145 other parts of the hardware via :c:func:`edac_device_alloc_ctl_info` function.
152 This set of structures and the code that implements the APIs for the same, provide for registering …
155 - CPU caches (L1 and L2)
156 - DMA engines
157 - Core CPU switches
158 - Fabric switch units
159 - PCIe interface controllers
160 - other EDAC/ECC type devices that can be monitored for
163 It allows for a 2 level set of hierarchy.
165 For example, a cache could be composed of L1, L2 and L3 levels of cache.
175 /L1-cache/ce_count
177 /L2-cache/ce_count
180 /L1-cache/ce_count
182 /L2-cache/ce_count
188 .. kernel-doc:: drivers/edac/edac_device.h
192 ----------------------------
194 An AMD heterogeneous system is built by connecting the data fabrics of
200 Each UMC contains eight channels. Each UMC channel controls one 128-bit
202 of 4096-bits of DRAM data bus.
205 channel is interfacing 2GB of DRAM (represented as rank).
209 GPU DF / GPU Node -> EDAC MC
210 GPU UMC -> EDAC CSROW
211 GPU UMC channel -> EDAC CHANNEL
218 - The CPU UMC (Unified Memory Controller) is mostly the same as the GPU UMC.
221 - CPU UMCs use 1 channel, In this case UMC = EDAC channel. This follows the
223 - CPU UMCs use up to 4 chip selects, So UMC chip select = EDAC CSROW.
224 - GPU UMCs use 1 chip select, So UMC = EDAC CSROW.
225 - GPU UMCs use 8 channels, So UMC channel = EDAC channel.
232 following those of the CPU nodes after latter are fully populated::
235 mc0 - CPU MC node 0
237 mc2 |- GPU card[0] => node 0(mc1), node 1(mc2)
239 mc4 |- GPU card[1] => node 0(mc3), node 1(mc4)
241 mc6 |- GPU card[2] => node 0(mc5), node 1(mc6)
243 mc8 |- GPU card[3] => node 0(mc7), node 1(mc8)
259 │ │ ├── channel 1 # size of each channel is 2 GB, so each UMC has 16 GB