Dimm Types; Minimum/Maximum Memory Size Per Configuration - Intel 460GX Software Developer’s Manual

Figure 5-2
time. It would then be muxed by the MDC to the SDC and then by the SDC to the bus. This allows
data to be moved with no dead cycles on consecutive reads. Another possibility is that the data
from cardA is going to the system bus, while the data from cardB is going to a PCI port. Since each
memory interface can support the transfer rate of 266 MT/s, data transfers to PCI are completely
overlapping transfers to the system bus such that there are no holes in the data traffic.
Table 5-2
460GX chipset.
Table 5-2. Minimum/Maximum Memory Size per Configuration
Technology & Configuration
16 Mb
64 Mb
128Mb
256 Mb
5.1.1

DIMM Types

The 460GX will support PC-100 DIMM's that meet the requirements defined in
The only DIMMs supported are 3.3 volt 168 pin (x72) parts. These may be composed of 16Mb,
64Mb or 256Mb DRAMs. The 256Mb DRAMs must have a supply voltage of 3.3 volts.
The DIMMs used must have the serial presence detect (SPD) feature, since this is used to program
the chipset configuration registers. DIMMs not having SPD will be considered as not-present in the
system, since they are not visible to firmware.
DIMMs may have a buffer on the DIMM itself. The buffer can be used in a registered mode or a
pass-through mode. The 460GX will support both buffered and unbuffered DIMMs. It will support
the buffered DIMM in the pass-through mode, not the registered mode. Thus the timings of the
state machines in the MAC will be the same for both types of DIMM. DIMMs with 36 components
will be buffered. DIMMs with 9 or 18 components may be buffered.
Intel® 460GX Chipset Software Developer's Manual
for an illustration. In theory all 4 of these lines could be transferring data at the same
gives a summary of the characteristics of memory configurations supported by the
DRAM
2M x 8 2M x 72
2M x 8 2Mx72x2
4M x 4 4M x 72
4M x 4 4M x 72 x 2
8M x 8 8M x 72
8M x 8 8M x 72 x 2
16M x 4 16M x 72
16M x 4 16M x 72 x 2
16M x 8 16M x 72
16M x 8 16M x 72 x 2
32M x 4 32M x 72
32M x 4 32M x 72 x 2
32M x 8 32M x 72
32M x 8 32M x 72 x 2
64M x 4 64Mx72
64M x 4 64M x72 x 2
Double Number of
DIMM
Sided? Chips/
Size
(Yes/no)
No 9
Yes 18
No 18
Yes 36
No 9
Yes 18
No 18
Yes 36
No 9
Yes 18
No 18
Yes 36
No 9
Yes 18
No 18
Yes 36
Memory Subsystem
Memory Size
DIMM
Min
64 MB 1 GB
128 MB 2 GB
128 MB 2 GB
256 MB 4 GB
256 MB 4 GB
512 MB 8 GB
512 MB 8 GB
1 GB 16 GB
512 MB 8GB
1 GB 16 GB
1 GB 16 GB
2 GB 32 GB
1 GB 16 GB
2 GB 32 GB
2 GB 32 GB
4 GB 64 GB
Table 5-3.
Max
5-3