IBM X3500 - Manual (Page 4)

A stable, long-life, dual-socket, dual- and quad-core SMP
server, offering high-performance, massive capacity and
outstanding availability
Please see the Legal Information section for important notices and information.
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Intel Extended Memory 64 Technology (EM64T) 64-bit extensions allow the Xeon processor to use large
memory addressing when running with a 64-bit operating system. This in turn lets individual software
processes directly access more than 4GB of RAM, which was the limit of 32-bit addressing. This can result
in much higher performance for certain kinds of programs, such as database management and CAD.
Additional registers and instructions (SSE3) can further boost performance for applications written to use
them. Contact your software provider to determine their software support for EM64T.
The 1066MHz FSB (which connects memory to the processor) boasts a peak rate of up to 8.53GBps, or
up to one-third higher throughput at the same processor clock speed than an 800MHz FSB (6.4GBps)
used in older systems. The 1333MHz FSB offers a peak rate of up to 10.67GBps, or up to two-thirds
higher throughput at the same processor clock speed than an 800MHz FSB. This may result in much
higher data transfer rates.
Intelligent Power Capability powers individual processor elements on and off as needed, to reduce
power draw.
Execute Disable Bit functionality can help prevent certain classes of malicious buffer overflow attacks
when combined with a supporting operating system.
DDR II ECC Fully Buffered Memory with Chipkill Protection
The x3500 supports up to 48GB of memory in 12 DIMM sockets. It uses PC2-5300 fully-buffered double
data rate II (DDR II) memory (operating at 667MHz) for faster access, and provides advanced Chipkill
memory protection, for up to 16X better error correction than standard ECC memory.
The fully buffered memory in the x3500 provides up to triple the memory bandwidth (up to 21.3GBps in
four channels of PC2-5300 fully-buffered DIMMs vs. a maximum of 6.4GBps in two channels of unbuffered
PC2-3200 memory) and up to
triple the system memory capacity (12 DIMMs x 4GB) of the predecessor
x236 server (8 DIMMs x 2GB). By performing reads and writes simultaneously, it eliminates the previous
memory read-to-write blocking latency. In addition, it also offers innovative data reliability and security
features to help improve data integrity, including enhanced CRC protection, data retry on error detect and
buffer registers for improved fault isolation.
For increased availability, the x3500 offers two additional (but mutually exclusive) levels of IBM Active
Memory protection: online
memory mirroring, and online hot-spare memory.
Memory mirroring works much like disk mirroring. The total memory is divided into two channels. Data is
written concurrently to both channels. If a DIMM fails in one of the DIMMs in the primary channel, it is
instantly disabled and the mirrored (backup) memory in the other channel becomes active (primary) until
the failing DIMM is replaced. Mirroring can be accomplished with multiples of four DIMMs (one pair per
memory channel).
When online hot-spare memory is enabled, using single and/or dual-rank DIMMs one rank is set aside per
channel as online spares in case one of the other ranks in that channel fails. The spare rank must have
capacity at least that of the largest active rank. (In other words, if a combination of 2GB and 4GB DIMMs
are used in a branch, one rank on each 4GB DIMM will be used for sparing.) In an x3500 with
48GB
installed, up to 40GB (using 12 dual-rank 4GB DIMMs) of memory is available when the hot-spare feature
is active.
Either of these features requires operating system support.
When multiples of four DIMMs (4/8/12) are installed, the x3500 operates in four-way interleaved mode,
for higher performance. When only two DIMMs are used, the system defaults to two-way interleaved
mode.
DIMMs must be installed in pairs. Memory is available in kits consisting of two 512MB, 1GB, 2GB or 4GB
DIMMs.
Hot-Swap/Redundant Components
System availability is maximized through the extensive use of hot-swap and redundant components,
including:
• Redundant memory protection (with online hot-spare memory or memory mirroring enabled)
• Hot-swap, redundant hard disk drives (with RAID-1/10/1E/5/6 protection)
• Hot-swap, redundant power supplies (optional)
• Hot-swap, redundant cooling fans (optional)
High-Performance Adapter Slots
The x3500 provides two x8 (“by 8”) 4GBps PCI-E (PCI Express) full-length/full-height adapter slots
( Slots 2 and 3). Each is capable of supporting x1/x4/x8 adapters at full speed. Slot 1 is a half-length/full-
height x4 (2GBps) PCI-E slot; Slots 4 and 5 are full-length/full-height (1GBps) 133MHz PCI-X slots,
and
Slot 6 is a half-length/full-height 33MHz legacy PCI slot.
PCI-Express is a high-performance, low-latency, next-generation serial I/O bus that is rapidly replacing