Update Intel Haswell MEM.txt

See #615

groups/haswell/MEM.txt

@@ -21,16 +21,14 @@ Memory data volume [GBytes] 1.0E-09*(MBOX0C1+MBOX0C2)*64.0
 
 LONG
 Formulas:
-L3 load bandwidth [MBytes/s] = 1.0E-06*L2_LINES_IN_ALL*64.0/time
-L3 load data volume [GBytes] = 1.0E-09*L2_LINES_IN_ALL*64.0
-L3 evict bandwidth [MBytes/s] = 1.0E-06*L2_TRANS_L2_WB*64.0/time
-L3 evict data volume [GBytes] = 1.0E-09*L2_TRANS_L2_WB*64.0
-L3 bandwidth [MBytes/s] = 1.0E-06*(L2_LINES_IN_ALL+L2_TRANS_L2_WB)*64/time
-L3 data volume [GBytes] = 1.0E-09*(L2_LINES_IN_ALL+L2_TRANS_L2_WB)*64
+Memory read bandwidth [MBytes/s] = 1.0E-06*(DRAM_READS)*64.0/runtime
+Memory read data volume [GBytes] = 1.0E-09*(DRAM_READS)*64.0
+Memory write bandwidth [MBytes/s] = 1.0E-06*(DRAM_WRITES)*64.0/runtime
+Memory write data volume [GBytes] = 1.0E-09*(DRAM_WRITES)*64.0
+Memory bandwidth [MBytes/s] = 1.0E-06*(DRAM_READS+DRAM_WRITES)*64.0/runtime
+Memory data volume [GBytes] = 1.0E-09*(DRAM_READS+DRAM_WRITES)*64.0
 -
-Profiling group to measure L3 cache bandwidth. The bandwidth is computed by the
-number of cache line allocated in the L2 and the number of modified cache lines
-evicted from the L2. This group also output data volume transferred between the
-L3 and  measured cores L2 caches. Note that this bandwidth also includes data
-transfers due to a write allocate load on a store miss in L2.
+Profiling group to measure memory cache bandwidth. The desktop-class Intel
+chips provide free-running memory counters in the MMIO space. Since they are
+free-running, it might overflow without notice if the read intervals are too long.