Checking for Hyper-threading and SSE4

Hi all,

How do I check if my processor supports hyper-threading and SSE4?

I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.

Also, is SSE4 only supported by Core i7?

Thank you.

Regards,
Rayne

Rayne wrote:
Hi all,

How do I check if my processor supports hyper-threading and SSE4?

I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.

I can only assume that when Linux say that HT is supported, they are
simply talking about the general HT flags, which are also used to
identify multiple physical cores, and not just virtual cores. BTW, what
version of Linux are you using? Perhaps its an old kernel?

Also, is SSE4 only supported by Core i7?

Should be supported from Pentium 4 all of the way upto Core i7.

Yousuf Khan

On Jan 19, 9:02 pm, Yousuf Khan wrote:
Rayne wrote:
Hi all,

How do I check if my processor supports hyper-threading and SSE4?

I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.

I can only assume that when Linux say that HT is supported, they are
simply talking about the general HT flags, which are also used to
identify multiple physical cores, and not just virtual cores. BTW, what
version of Linux are you using? Perhaps its an old kernel?

Also, is SSE4 only supported by Core i7?

Should be supported from Pentium 4 all of the way upto Core i7.

Yousuf Khan

I'm using Linux 2.6

Rayne wrote:
On Jan 19, 9:02 pm, Yousuf Khan wrote:
Rayne wrote:
Hi all,
How do I check if my processor supports hyper-threading and SSE4?
I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.
I can only assume that when Linux say that HT is supported, they are
simply talking about the general HT flags, which are also used to
identify multiple physical cores, and not just virtual cores. BTW, what
version of Linux are you using? Perhaps its an old kernel?

Also, is SSE4 only supported by Core i7?
Should be supported from Pentium 4 all of the way upto Core i7.

Yousuf Khan

I'm using Linux 2.6

No worries, I just ran the same command on my machine and it came back
showing SSE2 and HT as well. The difference is my processor is an AMD
Phenom II X3, and no AMD processor has ever supported Hyperthreading
(Hypertransport, yes, Hyperthreading, no). So since the HyperThreading
flag shows up on an AMD processor, I am now convinced it simply means
that it uses the Hyperthreading method of enumerating all kinds of
cores, both physical and virtual.

It also didn't mention SSE3, but does mention SSE4A (an AMD subset of
Intel's SSE4). I think SSE3 was simply a minor upgrade of SSE2, and the
"misalignsse" flag is the major differentiator over SSE2.

Intel also released another superset instruction set called SSSE3
(Supplemental SSE3), which AMD never supported. This is often mistakenly
called SSE4. The Intel true SSE4 (rather than SSSE3) is also forked into
not just an Intel & AMD version, but Intel's own version is forked into
an SSE4.1 (Penryn, on), and a SSE4.2 (Core i7, on). With all of this
forking and confusion that's going on now, I suspect that Linux will
never support anyone's SSE extensions beyond SSE2 & MisalignSSE.

If you really want to see the full capabilities of your processor,
you'll have to use CPU-Z and that runs on Windows.

Yousuf Khan

Yousuf Khan wrote:
Rayne wrote:
On Jan 19, 9:02 pm, Yousuf Khan wrote:
Rayne wrote:
Hi all,
How do I check if my processor supports hyper-threading and SSE4?
I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.
I can only assume that when Linux say that HT is supported, they are
simply talking about the general HT flags, which are also used to
identify multiple physical cores, and not just virtual cores. BTW, what
version of Linux are you using? Perhaps its an old kernel?

Also, is SSE4 only supported by Core i7?
Should be supported from Pentium 4 all of the way upto Core i7.

Yousuf Khan

I'm using Linux 2.6

No worries, I just ran the same command on my machine and it came back
showing SSE2 and HT as well. The difference is my processor is an AMD
Phenom II X3, and no AMD processor has ever supported Hyperthreading
(Hypertransport, yes, Hyperthreading, no). So since the HyperThreading
flag shows up on an AMD processor, I am now convinced it simply means
that it uses the Hyperthreading method of enumerating all kinds of
cores, both physical and virtual.

AFAIK the ht flag means that the cpu reports the cores and siblings properly. As
for sse[34] variants, my older 6600 doesn't, my q9400 has sse4_1 flag. I could
check others, but the specs are online and the CPUs aren't, so job for the curious.

* Rayne:

How do I check if my processor supports hyper-threading and SSE4?

I have an Intel Xeon E5405 @ 2.00GHz running Linux, and the flags
column in /proc/cpuinfo displays ht and sse2. However, the Intel
website (http://ark.intel.com/Product.aspx?
id=33079&processor=E5405&spec-codes=SLAP2,SLBBP) says that HT is not
supported by Intel Xeon E5405.

The intel website is right. None of the Xeon 5400 series supports
HyperThreading (it was burried with the old NetBurst XEON 5000 and only
revived with the Nehalem-based XEON 5500).

However, it does support SSE4.

Also, is SSE4 only supported by Core i7?

No.

Benjamin