About the difference of embedded graphics chip of x6412j and x6425e

[HuHao]

Hello everyone!

I was running a lightweight game under environment of j6412 and it worked fine.

Yesterday I upgraded (changed the device) to x6425e, and found the game's fps dropped down about a half.

I found in the specifications below it mentioned the graphics base frequency of x6425e is higher than j6412, and the number of execution units is about twice of j6412:

https://www.intel.co.jp/content/www/jp/ja/products/sku/207907/intel-atom-x6425e-processor-1-5m-cache-up-to-3-00-ghz/specifications.html

My question is:

Is this the expected behavior that the fps is not related to its frequency and number of execution units?

Am I missing some settings to make it run correctly?

* The game isn't use much CPU resource , and not read/write disk or transfer network data at all.

Any information is appreciated. Thank you!

[CarlosAM_INTEL]

Hello, @HuHao:

Thank you for contacting Intel Embedded Community.

You may find highlighted the differences between the cited processors on the following website:

https://ark.intel.com/content/www/us/en/ark/compare.html?productIds=214758,207907

Best regards,

@CarlosAM_INTEL.

[OTS]

This behavior could be caused by a bug in the driver.

I experienced a similar behaviour when using 2 different drivers for the same device.

• One driver delivered about 13 FPS at 100% CPU load and
• one driver delivered 72 FPS (which is the maximum the refresh limiter allows) at 2 or 3% CPU load.

Differences in software speed often outmatch differences in hardware speed.

[HuHao]

Thank you very much OTS! Really appreciate for your information.

May I know which device's driver did you changed? (GPU's driver?)

[OTS · Accepted solution]

Hello @HuHao ,

yes, I used a different graphics driver.

The system was using the original graphics driver from Microsoft with a graphics settings driver (vga.sys) which uses a very slow 16 color frame buffer driver (vga.dll).

This driver was replaced with a graphics settings driver written by a hobby programmer. The new graphics settings driver uses a much faster frame buffer driver (I think it's framebuf.dll from Microsoft) with more than 16 colors.

You are probably not using the 16 color frame buffer driver but my case showed how big the speed difference can be, when the driver is slow (for what reason ever).

In my opinion the hardware differences in your case does not explain the speed difference. I would expect both graphics circuits to have more or less exactly the same speed with the game in question. Your game does not seem to use multiple execution units. If it was that demanding then the CPU load on your j6412 system would be higher as it is the case with some modern 3D games.

So my guess is, that the problem is software related.

[HuHao]

Hello OTS

Thank you very much for your information!

My game is a lightweight game, but it seems to be using the modern game engine so the bottle-neck I think is in the fragment shader. Since the x6425e has more execution unit, I'd expected it should be more faster. However it is based on Atom instead of Celeron that j6412 based on, maybe this is the reason that FPS dropped.

I did some test using online 3D benchmark site and the x6425 can at most run 80% of j6412's score.

Anyway thank you for your help!

[OTS]

I see. Well then maybe I was completely wrong.

Anyway, if you think that the bottleneck is the shaders:

• Atom x6425e has 256 shaders.
• Celeron j6412 has 128 shaders.

[HuHao]

Thank you very much OTS!

Can you share me where did you get those information? 

[OTS]

Yes, of course @HuHao. Here is my source. It's an inofficial one because I have not found any official documentation on the graphics circuit

• Celeron J6412 16 EU, 128 shaders 
• Atom x6425E 32 EU, 256 shaders 

[HuHao]

Thank you OTS!!!

The site above is just what I was looking at for! Really appreciated!

P.S. Due to the information above, x6425E should have twice performance than J6412, but my device's real performance is x6425RE ? But in my system it actually displayed as "Intel Atom(R) x6425E Processor @ 2.00Ghz 2.00Ghz"

It's very strange.

I'll share here if I've found more information. 

Thank you all.

[HuHao]

I did some test about the graphics card's memory bandwidth, and found the J6412's memory bandwidth is more than 40GB/s while x6425E's only 6GB/s.

Currently the difference seems because the J6412 is using two memory slots which constructed as the "dual channel" architecture, while the x6425E is using only one memory slot, which refers to the "single channel" architecture.

I'm not sure the FPS is affected by this, just for your information. Thanks.