So dual channel Doesn't mean double speed? Newbie to pc gaming here...

[Jorge_acosta]

Hello everyone, first of all, this is my current setup

Gigabyte F2A68HM-S1 Motherboard
AMD A8-7600 Radeom R7 250 APU
Saphire AMD R7 250 2gb DDR3 working on Dual Graphics with the APU
16GB RAM (8gb ddr3 HyperX Fury 1600Mhz + 8gb ddr3 HyperX Blu 1600Mhz)
320GB HDD 5900 rpm Seagate
Running Windows 10




I recently bought a custom PC, intended for some mid-level gaming. I originally bought it with a Hyperx Fury 8gb RAM 1600mhz stick, but recently I found a great price on a Hyper x Blu 8gb 1600Mhz used unit online, so i bought it becouse on my limited knowlege i thught: "Extra RAM never hurts, and since these two sticks are both HyperX 8gb 1600Mhz sticks i can get them to work on dual channel, the fact that one is a "fury model" and the other a "blu model" doesn't matter".

So i got the new stick, installed it in my motherboard and that was it, pc started up fine, and it detected the new stick although i don't know why some hardware detection Software say i have 15gb RAM and others say 16gb RAM. Checking with CPU-Z Software it lists my memory channel as "DUAL".

So recently i started reading a little more on this whole PC performance subject, and found out a few things:

a) According to the internet for dual channel to work both RAM sticks have to be identical, prefferably bought at the same time.

b) APUs like the one i have on my rig benefit a lot from faster RAM



So I guess that my questions are:

1) Can I trust CPU-Z?? even if my sticks aren't identical am i running in Dual channel?

2) Is Dual Channel even worth it? i the performance upgrade on this rig should be noticeable?

3) Given the fact that i have a APU working in dual graphics with de GPU, would it be better to have less ram but with faster frequency? say a HyperX fury 8gb 2400mhz??


Sorry, for the lengthy post, hope you guys can help me out.

 

[Tradesman1]

Yes, it's possible to run dual dual with non-'identical' DRAM and has been for years now. Dual channel 'could' theoretically double the 'speed', but in actuality it's more like a 10-15% performance increase, which, Yes, is worth it With An APU and using it's iGPU it's definitely worth worth it...yu want both more DRAM and faster DRAM...the iGPU benefits from faster DRAM (GPU can run faster) and the more DRAM, because unlike a discrete GPU card that has it's own vRAM, the iGPU uses your system DRAM leaving less for the OS and Apps

There are many myths floating about DRAM, mike take a look at my FAQs and Fiction article, which addresses many of them:

http://www.tomshardware.com/answers/id-2741495/ddr3-faqs-fiction.html

 

[blazorthon]

For CPU performance, dual-channel memory typically only provides about a 10% to 15% increase in performance, but that's because that's all the CPU can really use. The bandwidth is practically almost doubled and the integrated GPU of an APU can take advantage of this bandwidth, unlike the CPU. So, dual-channel is very important for APUs.

Capacity is not very important past 8GB, so yes, going higher in capacity does not improve performance because games don't use that much RAM. Higher frequencies, like going dual-channel, will increase bandwidth and similar to going dual-channel from single, the CPU does not really get much more performance out of this whereas the integrated graphics can get a large performance boost. So, dual-channel, high-frequency 8GB memory is ideal for APU gaming systems. 2x4GB kits make the most sense for getting 8GB because 4x2GB kits are more expensive and have inferior performance despite their higher cost.

However, 16GB does help in multi-tasking when you're actually using that much RAM. Playing games without multi-tasking does not benefit from more than 8GB.

Using non-identical RAM is not as good as using identical RAM, but this is mostly because non-identical RAM is not guaranteed to work. If you already have the modules, there is nothing wrong with trying it to see if it works, but if you were looking to buy two modules from different kits, then it is not a good idea because they might not work right together (even if their specs are the same).

 

[Jorge_acosta]

Thank you both for your answers!! i think i get it now. Could you also help me with why CPU-Z lists these:


Channel #: Dual
NB Frequency: 1596.8 MHZ <<--- I think this is ok since both my ram sticks are 1600Mhz
DRAM Frequency: 665.3 MHz <<---- Shouldn't this be 800mhz??

 

[Tradesman1]

For CPU performance, dual-channel memory typically only provides about a 10% to 15% increase in performance, but that's because that's all the CPU can really use. The bandwidth is practically almost doubled and the integrated GPU of an APU can take advantage of this bandwidth, unlike the CPU. So, dual-channel is very important for APUs.

Capacity is not very important past 8GB, so yes, going higher in capacity does not improve performance because games don't use that much RAM. Higher frequencies, like going dual-channel, will increase bandwidth and similar to going dual-channel from single, the CPU does not really get much more performance out of this whereas the integrated graphics can get a large performance boost. So, dual-channel, high-frequency 8GB memory is ideal for APU gaming systems. 2x4GB kits make the most sense for getting 8GB because 4x2GB kits are more expensive and have inferior performance despite their higher cost.

However, 16GB does help in multi-tasking when you're actually using that much RAM. Playing games without multi-tasking does not benefit from more than 8GB.

Using non-identical RAM is not as good as using identical RAM, but this is mostly because non-identical RAM is not guaranteed to work. If you already have the modules, there is nothing wrong with trying it to see if it works, but if you were looking to buy two modules from different kits, then it is not a good idea because they might not work right together (even if their specs are the same).

--------------------------------

You say 8GB is plenty with a iGPU in gaming, so if you have 8GB, the IGPU uses say 2.5 of that it leaves you with 5.5 of system DRAM for OS and game - what about games that need 8GB or the newer and upcoming that call for 16GB ? If getting DRAM I would want to look not onaly at 'today' but down the road a bit also

 

[blazorthon]

The NB frequency is not directly tied to the RAM< it is directly tied to the highest value supported by both the motherboard and the CPU. About 1.6GHz (3.2GT/S) is normal.

You are correct about the DRAM frequency. This may be related to you mixing kits because the motherboard doesn't know what to do since the two memory kits have different settings, so the board just defaulted to the lower frequency of DDR3-1333. When mixing kits works, you usually need to set higher frequencies and lower timings manually.

 

[blazorthon]

For CPU performance, dual-channel memory typically only provides about a 10% to 15% increase in performance, but that's because that's all the CPU can really use. The bandwidth is practically almost doubled and the integrated GPU of an APU can take advantage of this bandwidth, unlike the CPU. So, dual-channel is very important for APUs.

Capacity is not very important past 8GB, so yes, going higher in capacity does not improve performance because games don't use that much RAM. Higher frequencies, like going dual-channel, will increase bandwidth and similar to going dual-channel from single, the CPU does not really get much more performance out of this whereas the integrated graphics can get a large performance boost. So, dual-channel, high-frequency 8GB memory is ideal for APU gaming systems. 2x4GB kits make the most sense for getting 8GB because 4x2GB kits are more expensive and have inferior performance despite their higher cost.

However, 16GB does help in multi-tasking when you're actually using that much RAM. Playing games without multi-tasking does not benefit from more than 8GB.

Using non-identical RAM is not as good as using identical RAM, but this is mostly because non-identical RAM is not guaranteed to work. If you already have the modules, there is nothing wrong with trying it to see if it works, but if you were looking to buy two modules from different kits, then it is not a good idea because they might not work right together (even if their specs are the same).

--------------------------------

You say 8GB is plenty with a iGPU in gaming, so if you have 8GB, the IGPU uses say 2.5 of that it leaves you with 5.5 of system DRAM for OS and game - what about games that need 8GB or the newer and upcoming that call for 16GB ? If getting DRAM I would want to look not onaly at 'today' but down the road a bit also

The IGP doesn't need anywhere close to 2.5GB. Even giving it more than 1GB is pointless because that won't improve its performance at all. Also, IGPs don't typically reserve so much RAM. They only reserve small amounts (if any at all) and share the rest with the CPU as needed.

No games currently need a computer to have more than 8GB unless you are multitasking and I don't see this changing, at least not with settings that integrated graphics can perform in without slowing the FPS to a slide show. You see arguments like this say with a Radeon 7750 2GB over the 1GB model of the card and many other similar cases with other lower end cards with a lot of memory. In any game settings that need more than 1GB, the 7750's GPU is too slow anyway, so why bother getting a 2GB model? Same problem. If you want to paly a game that needs 2.5GB of video memory, you need a high-end graphics card and you probably want a stronger CPU as well.

So, yes, tomorrow's games may call for more memory, but today's integrated graphics are too weak to make use of more memory, so it's a moot point. Furthermore, tomorrows APUs won't fit in today's motherboards, so there isn't even the argument of waiting to upgrade the APU.

 

[Jorge_acosta]

The NB frequency is not directly tied to the RAM< it is directly tied to the highest value supported by both the motherboard and the CPU. About 1.6GHz (3.2GT/S) is normal.

You are correct about the DRAM frequency. This may be related to you mixing kits because the motherboard doesn't know what to do since the two memory kits have different settings, so the board just defaulted to the lower frequency of DDR3-1333. When mixing kits works, you usually need to set higher frequencies and lower timings manually.

But both Sticks are supoused to be 1600mhz... The only difference that i know of is that the fury has CL10 and the blu has CL9 (whatever that means)

So you are saying that i am hurting performance by having the extra stick??

 

[blazorthon]

But both Sticks are supoused to be 1600mhz... The only difference that i know of is that the fury has CL10 and the blu has CL9 (whatever that means)

So you are saying that i am hurting performance by having the extra stick??

The problem is that with different timings and other things, the motherboard doesn't know what to do. Both of the sticks are also meant to be used alone, so their secondary timings are tighter than is possible with them being used together because using two memory sticks puts slightly higher stress on the memory controller. This can be addressed, again, by manually configuring the memory performance in the BIOS because the BIOS doesn't know what to do on its own when you mix memory kits.

Sometimes you need to bump the voltage up a bit, sometimes you need to loosen the secondary timings a bit, or both when mixing memory kits. Sometimes you just need to set the proper timings and frequency for the slowest module (IE DDR3-1600 CAS 10) and you're good to go. If you want DDR3-1600, then you need to set it yourself and see how it handles.

If you don't fix the memory settings yourself, then you are still better off in dual channel because 2x DDR3-1333 is better than 1xDDR3-1600, especially for the integrated graphics.

 

[Tradesman1]

The Fury runs off PnP, and your other is a 'normal' XMP stick, these often have problems playing, best to set manually, prob 1600 10-10-10-27 1.55. As far as memory scaling and use, PCPER did this showing using 2GB

http://www.pcper.com/reviews/Memory/Ultra-Speed-DDR3-Revisited-AMD-APU-Memory-Scaling/Test-System-and-Overclocking

Tom's also did an article osn scaling :

http://www.tomshardware.com/reviews/memory-bandwidth-scaling-trinity,3419.html

 

[Jorge_acosta]

Ok, thank you both for your help, it has teached me a lot, but i think i rather buy a new two stick set, (HyperX Fury 8gb 2400 mhz) and don't mess with the bios. Becouse of your answers i gather that i should get the most out of my APU this way, am i right??

 

[Tradesman1]

Correct and a set coming in a single package the sticks are tested to play together