What is the difference between minicomputers and PC servers?
From various performance evaluation indicators to the processing capability of a single CPU, minicomputers do not seem dominant. Why is it expensive?
We can analyze the characteristics of performance, reliability, and scalability.
For a single CPU, the Intel Xeon or AMD opteron used by PC servers is not inferior to the CPU performance used by minicomputers. However, the operating system released on the PC Server supports a maximum of 16 CPUs (the latest operating systems can also support more CPUs, or even Unix to achieve the same level of support, for example, Windows 2003 data center 64bit, which puts more and more pressure on Unix servers)
In contrast, on a minicomputer, the total number of CPUs integrated by one machine has reached dozens to hundreds. Currently, the IBM p595 and aix6.1 operating systems support 64 power6 5 GHz CPUs (p595 with 128 CPUs will be released soon ); HP's Superdome uses a PA-8900 or Intel itanium 2 chip to support 128 CPUs, and Sun's m9000 uses a 64-VI chip to support 128 CPUs (cores ). This super parallel processing capability leaves PC servers and Windows operating systems far behind. (Windows 2003 datacenter 64-bit edition also supports up to 64 CPUs.) although the processing capacity cannot grow linearly when the CPU usage increases, 80 CPUs are always faster than 8 CPUs (in the case of similar clock speed and manufacturing process and technology)
Not only is the hardware processing capability, but the management capability of the operating system is very important. It requires a very complex technology to fully mobilize dozens of CPUs and exert the capabilities of each CPU. In addition, the operating system also needs to manage some memory processes. If a process has problems (such as an endless loop), it may exhaust the system resources. At the beginning of the design, Unix was designed to better coordinate the scheduling among multiple users and multi-process scheduling. Generally, these resource-consuming processes can be better controlled, reasonably allocate CPU processing capabilities among processes. At last, Unix generally does not provide complex multimedia and graphical interfaces, and these beautiful user interfaces are indeed a large user of CPU and memory consumption.
Because of the above reasons, in the low-end market, Minicomputers are completely at a disadvantage, but at the high end, the situation began to reverse, and only minicomputers can afford heavy processing tasks (of course there are mainframe mainframes ).
Strong processing capability not only depends on the CPU, but also indicates the computing capability. The CPU also requires Io support. If the machine cannot accept the request in time, the results cannot be returned or saved after the computation is complete, powerful computing capabilities are useless, or they can only be used in specific computing fields. Generally, the minicomputer system can support a maximum of one hundred I/O channels, provide sufficient bandwidth to send or save the processing results from the network, and accept new tasks. Almost no PC has more than 10 iocards. When the business volume is large, the CPU is busy and I/O cannot be processed.
I/O controllers can not increase the number of processing cards at will. bus bandwidth restricts the number of iocards, memory and CPU that can be plugged in. Therefore, minicomputers often use special technologies to achieve almost crazy scalability. In contrast, PC and PC servers are more concerned with compatibility issues. They can be plugged into a variety of third-party interface cards, focusing on types rather than quantity, therefore, very special technologies cannot be used on interfaces. to be popular, compatibility is required, and performance is naturally compromised. These compatible cards are also hardware devices and operating systems that are more difficult to ensure stability and reliability. Generally, minicomputers do not have a few types of interface cards. However, compared with PCs, almost all of them produce their own interface cards (or OEM products from some well-known manufacturers). After a long period of testing, they can be released, therefore, the reliability is relatively good. PC is not the case. The design and production methods that everyone complies with the same standards are used to test their own stability. The interconnection test is also based on compatibility and performance, and the stability can be accepted as long as it is not too bad. Therefore, Windows often have blue screens and hardware crashes (to reduce this situation, we recommend that you only use the original Board ).
Because of the performance, reliability, and scalability of minicomputers, Minicomputers are more used in demanding commercial environments, such as billing and accounting departments of banks and communications, and production line control. In these fields, it is required to operate continuously for 7x24 hours, and the availability of a single machine is more than 99.9% of the annual availability (the cumulative downtime for the whole year is no more than 50 hours, including planned overhaul and unplanned equipment failure) the number of dual-host servers reaches 99.99% (service interruption time within 53 minutes throughout the year)
There are many differences between minicomputers and PC servers. Table 1-1 briefly compares these differences (for example, IBM pseries minicomputers and xseries PC servers, and the corresponding indicators are the highest in the same series, may not be implemented on the same server ).
Project |
IBM minicomputers |
Ibm pc Server |
CPU type |
IBM power 6 |
Intel Xeon, Ia 64 |
CPU clock speed |
5 GHz |
4.2 GHz |
CPU Technology |
DCM, MCM, SMP, numa |
DCP, SMP |
Level 1 Cache |
64 K d, 64 K 1, synchronization |
32 K |
Level 2 Cache |
4 MB, 160 Gb/s, Core |
1 MB |
Level 3 Cache |
32 MB, 45 Gb/s, Core |
None |
Maximum number of CPUs |
64 (currently released, with design support of 512) |
8-32 |
Maximum memory capacity |
2 TB ddr1/256 GB DDR2 |
64g DDR2 |
Memory bus frequency |
266 or 533 MHz |
533 MHz |
Memory Access Technology |
SmI 2 |
SmI 2 |
System Bus |
GX Bus |
None (Front-End bus) |
System bus bandwidth |
72 Gb/s |
6.4 Gb/s |
Io Bus |
PCI-X |
PCI-X |
Max iocard |
240 |
20 |
Hot swapping capability |
Almost all parts |
CPU and other key components cannot be hot-swappable |
Partition |
Hardware Partition (logical partition) |
Software partition (vmware/virtualpc) |
Maximum number of partitions |
1024 |
N. |
Partition Granularity |
0.1cpu |
1-4 CPU |
Partition Method |
Static, dynamic, and differential Zone |
Sharing, software partitioning |
Interval Load Adjustment |
Hardware and software) |
Dynamic partition software management |
Hardware Management |
Separate HMC |
Local console BIOS |
Operating System |
Aix, Linux |
Windows, Linux, Solaris |
Operating System Core |
Dynamic Kernel |
Static Kernel |
Commercial Software Support |
Various large commercial applications |
Start porting down from Minicomputer |
Because of its market strategy, IBM has not yet plans to run Windows on pseries minicomputers, nor has it plans to run AIX on x86/IA64 architectures. It is expected that one or two years later, IBM will complete the unification of the three major series (P, I, Z) in the four major series. It is undoubtedly necessary to consider the final unification of the X Series. What will happen at that time will be what we can only wait and see. The advanced virtualization alization enviroment feature is provided on the latest IBM minicomputer operating system aixv6.1 to directly run x86 Linux programs. This seems to reveal a bit of information: IBM will not leave a glimmer of life for Windows on Minicomputers, but it is open to Linux.
32 bit
Intel x86 ----------------------------------------------------------->
AMD x86 ----------------------------------------------------------->
64 bit
Intel itanimum ------------------------------------------------>
AMD opteron --------------------------------------------->
Intel x86-64 ---------------------------->
IBM power ----------------------------------------------------------->
HP PA-RISC ---------------------------------> (2007)
Sun ultraliscsi ----------------------------------------- (Fujitsu) ---->
Ibm hp Dell sun
IBM power intel itanimum intel itanium sun ultrasparc
High-end intel itanimum HP PA-RISC
Mid-range IBM power intel itanium sun ultrasparc
Intel itanimum HP PA-RISC
AMD opteron
Low-end IBM power intel itanium sun ultra iSCSI
Intel x86-64 intel X86-64 intel x86-64 amd opteron
Intel itanimum amd opteron
AMD opteron HP PA-RISC