IBM 170 manual Level 1 Cache, Level 2 Cache

Following is an example of the processor card information for a 333 MHz Model 170:

Processor Card:
Part Number	11K0857
EC Level	D72830
Serial Number	L200016008
FRU Number	00P2180
Manufacture ID	1980
Version	RS6K
Product Specific.(ZC)	PS=0013D92D40,LB=0009EC96A0,
	SB=0005ABC3C9,NP=01,L2=01024,
	PF=711,SV=3,VR=2,ER=0000
Product Specific.(ZB)	BC=30602,SG=
Physical Location: P1-C1

PS shows the processor speed in hex-number digit (0x0013D92D40 = 333000000 Hz = 333 MHz).

Following is an example of the processor card information for a 400 MHz Model 170:

Processor Card:
Part Number	11K0864
EC Level	D72830
Serial Number	L200016010
FRU Number	00P2181
Manufacture ID	1980
Version	RS6K
Product Specific.(ZC)	PS=0017D78400,LB=000BEBC200,
	SB=0005F5E100,NP=01,L2=04096,
	PF=7D4,SV=3,VR=2,ER=0000
Product Specific.(ZB)	BC=30602,SG=
Physical Location: P1-C1

PS shows the processor speed in hex-number digit (0x0017D78400 = 400000000 Hz = 400 MHz).

Level 1 Cache

The Model 170 uses a 64 KB data and 32 KB instruction 128-way set associative L1 cache. The size of both data and instruction cache reduces the number of cache misses, results in more cache hits, and maximizes performance. Both data and instruction cache are parity protected.

Level 2 Cache

The 44P Model 170 processor card has either 1 MB (333 MHz) or 4 MB

(400 MHz) of L2 cache located on the processor card. L2 cache is used to lower the time spent accessing memory data and increase performance. The L2 cache extends L1 cache benefits by adding more cache to the memory pipeline.

The speed of the L2 cache is dependent upon the processor speed. The L2 cache speed for the 333 MHz processor is 167 MHz (2:1 ratio) and for the 400 MHz processor is 200 MHz (2:1 ratio).

The L2 cache uses a direct mapped cache methodology. There is a dedicated external interface to the L2 cache not shared with the 6XX bus. This allows concurrent access to both the L2 cache and the 6XX bus.

6RS/6000 7044 Model 170 Technical Overview