CPU KL Pentiums have HT!

[IntoxicatedPuma]

http://www.tomshardware.com/news/intel-cpu-hyper-threading-pentium,33386.html

I guess this means Zen is going to be ultra competitive on the low end. We could see quad cores under $100? Pentium's @ 3.7ghz with HT for under $100

 

[confusis]

This is a rather weird decision. Does this mean KL Pentiums are just i3's with less cache? Kinda makes the (non-K) i3's not worth it as the price paid to improve perf over the Pentium would be...silly

(Looking at the pricing on the site, it looks like 30% premium for 1MB of L3 cache improvement and similar clocks)

 

[ricochet]

Hmmmm... the Pentium G4620 is looking rather appealing now. I was planning to get an KL i3 but now I may have to rethink that.

 

[Thehack]

Finally! CPU low end prices has been outrageous.

 

[Phuncz]

I kinda wished they kept the HT off of the Pentiums or atleast have non-HT models. Not everything is better with more cores, especially single-core stuff. But seeing as AMD and Intel are going this way, it might not be a point, for the future.

 

[Thehack]

I kinda wished they kept the HT off of the Pentiums or atleast have non-HT models. Not everything is better with more cores, especially single-core stuff. But seeing as AMD and Intel are going this way, it might not be a point, for the future.

Why? HT doesn't add more cores? Also. I don't see how adding HT is detrimental. Until you start hitting thermal headroom adding more cores don't affect single core performance.

 

[IntoxicatedPuma]

They still have non HT Pentiums so not to worry, only some are HT enabled.

 

[Brokoii]

I kinda wished they kept the HT off of the Pentiums or atleast have non-HT models. Not everything is better with more cores, especially single-core stuff. But seeing as AMD and Intel are going this way, it might not be a point, for the future.

You can always disable HT in the bios.

 

[ricochet]

You can always disable HT in the bios.

What would be the benefit to do this on a Pentium?

 

[Brokoii]

What would be the benefit to do this on a Pentium?

For multi threaded applications or programs that require 4 threads you could leave HT on and turn it off again if you don't need it.

 

[ricochet]

For example the new KL Pentium G4620 would leaving HT "ON" actually lessen this Pentium's performance on single threaded apps/programs?

 

[|||]

It's only with lightly threaded applications that hit the scheduler hard, does hyper-threading adversely affect the performance. I have seen benchmarks of games running better on an i5 than an i7, but just barely.

 

[ricochet]

So a KL Pentium G4620 would perform better at single-threaded apps (email, internet browsing, office word) with the HT turned "OFF"?

 

[|||]

If you have a lot of database calls or something else that requires a lots of I/O, the would be very taxing on the scheduler that manages the activity for both threads on a core with HT. I doubt typical email, browsing, or productivity apps will have any noticeable difference.

 

[ricochet]

Thank you for the explanation; understand much better now after researching CPU "scheduler". Cheers.

 

[BirdofPrey]

HT is only really going to be detrimental if CPU is at high utilization.
Hyperthreading (if you want to do some research, the technical term is Simultaneous Multithreading) does not actually change the computing resources of the core; what it does is allow more than one thread to share those resources since, often times, each core isn't 100% utilized.

If I am remembering correctly, Skylake (and by extension Kaby Lake) has 3 Arithmetic Logic Units (ALUs) and 2 Address Generation Units (AGUs). If one thread only needs to use 2 of the ALUs, that leaves 1 available for use. Whether or not HT is on won't affect that. You only start to see problems if both threads want to use 2 or 3 ALUs (granted it's more complicated than that, some instructions only work on certain ALUs/AGUs and the threads are sharing a cache), but it still generally works out the same: You're not going to see much difference on a per-program basis, if you do you need to rethink your choice of CPU.

 

[IntoxicatedPuma]

Just curious then, if I were say rendering a video on Adobe Premiere or something, would a G3258 @ 4.5ghz outperform a 3.8ghz Haswell i3? Since the CPU usage should be around 100%.

I'm not too familiar with this as well so I usually just assumed HT doesn't have many drawbacks.

 

[Therandomness]

This is a rather weird decision. Does this mean KL Pentiums are just i3's with less cache? Kinda makes the (non-K) i3's not worth it as the price paid to improve perf over the Pentium would be...silly

(Looking at the pricing on the site, it looks like 30% premium for 1MB of L3 cache improvement and similar clocks)

They're missing AVX, AVX2 and some other instruction set though.

 

[GuilleAcoustic]

Intel CPUs not reached Intel Chipsets on the non-sense hall of fame. It was already impossible for someone who doesn't follow tech news to choose an Intel chipset (too many of them) ... but now it will also we impossible to pick the right CPU.

Celeron are/were just Pentium with 1MB less of cache. Now Pentium are i3 with 1MB less of cache ..... Intel has too many chipsets, too many CPU with sometimes only 100MHz between each of them). Some CPU are more expensive than one with a faster base frequency ... because it can turbo a little higher (i5-4570 3.2 / 3.6 @ 239€ VS i5-4460 3.2 / 3.4 @ 194€ .... 23% premium for +200MHz turbo and no base clock boost).

 

[ricochet]

They're missing AVX, AVX2 and some other instruction set though.

Looks like the G4620 has AVX but not AVX2. Incorrect: Only SSE.4.1/4.2