专利公开号：US6493741 B1
专利名：Method and apparatus to quiesce a portion of a simultaneous multithreaded central processing unit
申请日期：1999年10月1日
申请人：Compaq Information Technologies Group, L.P.
链接：http://www.google.ca/patents/US6493741
世界第一台使用SMT技术的硬件：http://zh.wikipedia.org/wiki/DEC_Alpha
Compaq公司介绍SMT技术的ppt：http://www.cs.washington.edu/research/smt/papers/compaqMF.ppt

顺便查了下，AMD的CMT集群多线程（模块化的学名）技术及推土机架构的相关专利还真是多啊：
clustered multithreading with 2 int clusters with each of them having:
2 ALUs, 2 AGUs
one L1 data cache
scheduler, integer register file (IRF), ROB
(see 20080263373*, 20080209173, 7315935)
a trace cache, not to make cheaper decoders but to quickly recover from a mispredicted branch (7197630 and many others)
read port arbitration for a faster IRF (7315935)
shared FPU supporting ADD, MUL, FMAC etc. and 64 or 128 bit max. operand width (20080263373)
FPU may run in full bit or reduced bit modes to save power (20080209185)
32 byte fetch, 4-way Decoder - multithreaded round robin or depending on queue saturation (20080263373, EP1244962)
fine grained power management (token based, 20080263373) for optimal usage of given TDP/ACP
a lot more speculation (data speculation, cache way prediction, see 7024537, 7028166 and many others)
2 loads from L1 D$ per cycle per cluster (7502914)
maybe 2 cycle effective L1 D$ latency instead of 4 thanks to replaying (7502914)
possibly a shared L2 (7502914)
loop detectors (7130991)
dynamically scalable cache architecture to save power by switching off cache portions or levels (20080104324)
AMD's turbo mode (running cores faster if others are less utilized, 7490254, filed 2005/08/02)
链接在此：http://www.amdzone.com/phpbb3/viewtopic.php?f=52&t=136642&sid=7684996c4331959e9b922b0352ad9116

维基百科关于几种多线程技术的解释：http://zh.wikipedia.org/wiki/%E5%A4%9A%E7%BA%BF%E7%A8%8B

“这种技术可以同时处理2个以上程序，现在的单核只能处理1个任务，比如1微秒内，处理2个任务，可能处理一个任务0.5微秒后就必须暂停，处理另一个任务，这会消耗大量的时间，而让一个处理器同时处理他们（双线程）就不存在这种问题，这也就是超线程的意思”
@65186959 AMD那篇专利中没有你说的这种意思哦。现引用这篇专利一段话：
“Multiple ISR context storages allow for nested interrupts to be performed concurrently. In yet another embodiment, the microprocessor is configured to execute multiple tasks and multiple interrupt service routines concurrently. Multiple tasks may be executed concurrently by the microprocessor in addition to executing multiple interrupt service routines concurrently.”
再引用compaq公司那篇专利一段话：
“A simultaneous multithreaded (SMT) central processor unit (CPU) provides, on a single CPU, the capability of executing instructions from multiple threads simultaneously.
On a simultaneously-multithreaded processor, the hardware provides facilities for executing multiple threads as if each thread were executing on its own CPU. This abstract thread processor is called a thread processing unit, or TPU. To the outside world, a TPU has all the capabilities of a conventional CPU. It holds a full process context while a process or thread is executing on that TPU.”
看出来了吧，这两种技术中前者是“concurrently”（并发地），而后者是“simultaneously”（同步地），分明是两种不同的技术啊。I