Storage Versus In-Memory Data - IBM x3850 X6 Planning And Implementation Manual

Maximum configurations
Memory
2.5-inch drive
bays
1.8-inch SSDs
drive bays
Standard 1Gb
Ethernet
interfaces
Standard 10Gb
Ethernet
interface
USB ports
Power supplies
a. Requires all processors to be installed in order to use all memory slots.
b. Model dependent.
c. Mixing of power supplies in pairs is supported.

1.4 Storage versus in-memory data

Main memory (RAM) is the fastest storage type that can hold a significant amount of data.
Data in main memory can be accessed more than a hundred thousand times faster than data
on a spinning hard disk, and even flash technology storage is about a thousand times slower
than main memory.
Main memory is connected directly to the processors through a high-speed bus, whereas
hard disks are connected through a chain of buses (QPI, PCIe, SAN) and controllers (I/O hub,
RAID controller or SAN adapter, and storage controller).
Compared to keeping data on disk, keeping the data in main memory can dramatically
improve database performance just by the advantage in access time. However, there is one
potential drawback. In a database transaction that has been committed, the transaction
cannot stay committed.
x3750 M4
1-node 48 DIMM slots
1-node with Not available
MAX5
2-node Not available
1-node 16
2-node Not available
1-node 32
2-node Not available
1-node 2
2-node Not available
1-node 2 (Optional)
2-node Not available
1-node 4 USB 2.0
2-node Not available
1-node 2 x 1400W
2-node Not available
x3850/x3950 X5
a a
64 DIMM slots
a
96 DIMM slots
a
128 DIMM slots
8
16
16
32
b
2
4
2
4
8 USB 2.0
16 USB 2.0
2 x 1975W
4 x 1975W
Chapter 1. Introduction
x3850/x3950 X6
a
96 DIMM slots
Not available
a
192 DIMM slots
8
16
16
32
4 (Optional)
8 (Optional)
2 (Optional)
4 (Optional)
6 USB 2.0, 2 USB
3.0
12 USB 2.0, 4
USB 3.0
4 x 900W or
c
1400W
8 x 900W or
c
1400W
7