Utilizing Flex Mode 1x4 + 2x2

[iMxmo]

Hey all, little bit confused on how to utilize Intel Flex Tech. 

Buddy of mine is on an old Phenom II X4, and has 1x4Gb and 2x2Gb. Is Intel Flex supported on this platform?
If so, how would we go about making this work in the most optimal way? Mainboard has 4 DIMM slots. 

I was thinking something like 1x4 in Slot 1, and then the 2x2 in Slot 3 + 4. Leaving Slot 2 unoccupied. Or would 2x2 in Slots 1 + 2, and 1x4 in Slot 3/4 work better? If so, why? 

[Eigenvektor]

If flex mode is working, it means you can get dual channel even when mixing sticks like that. Dual channel increases your memory bandwidth/performance. You need to check the motherboard's manual to see which slots need to be occupied when using three memory sticks.

 

However, Phenom II X4 is AMD, so using Intel's Flex Tech… eh… no?

 

~edit: to be clear, it is possible Phenom II supports asymmetric memory loadouts. Unlike Intel, AMD does not use a marketing name like flex, so it is difficult to say for certain. Simply try it out. The.system may not boot, but it's not going to break anything.

[iMxmo]

8 hours ago, Eigenvektor said:

If flex mode is working, it means you can get dual channel even when mixing sticks like that. Dual channel increases your memory bandwidth/performance. You need to check the motherboard's manual to see which slots need to be occupied when using three memory sticks.

 

However, Phenom II X4 is AMD, so using Intel's Flex Tech… eh… no?

 

~edit: to be clear, it is possible Phenom II supports assymetric memory loadouts. Unlike Intel, AMD does not use a marketing name like flex, so it is difficult to say for certain. Simply try it out. The.system may not boot, but it's not going to break anything.

My thought was that modern AMD CPU's do support Intel Flex Tech, or well something similar. Wasn't quite sure because of the age of Phenom II X4. This was for a buddy of mine and kind of disappeared after recommending this. Previously, he had tried 2Gb Slot 1, 2Gb Slot 3, and 4Gb Slot 4. Don't know why it was set up like that, but Windows reported only 3GB usable memory (hwat.) I'm thinking we should finick around with the memory remapping setting for this. Thoughts? 

[Eigenvektor]

51 minutes ago, iMxmo said:

My thought was that modern AMD CPU's do support Intel Flex Tech, or well something similar.

I wouldn't exactly call a ~12 year old CPU modern. Modern would be something like Zen architecture, which does support asymmetric memory loadouts, afaik.

 

Which version/edition of Windows are we talking? 3 GB sounds suspiciously like a 32 bit version limitation.

[iMxmo]

1 hour ago, Eigenvektor said:

I wouldn't exactly call a ~12 year old CPU modern. Modern would be something like Zen architecture, which does support assymtric memory loadouts, afaik.

Yep, exactly why I was worried about flex/asymmetric. Task manager readout here: (Shows 8Gb being recognized, but only 3Gb memory usage..?) 


Still think the optimal layout is 1x4 in Slots 1/2, and 2x2 in 3 + 4. For 4Gb per memory channel. 

1 hour ago, Eigenvektor said:

Which version/edition of Windows are we talking? 3 GB sounds suspiciously like a 32 bit version limitation.

Not sure tbh, thought it was a memory remapping issue. Will keep updated as 'buddy' returns. 

[Eigenvektor]

1 hour ago, iMxmo said:

Yep, exactly why I was worried about flex/asymmetric.

The system should still be able to use all of the memory even if the CPU/board doesn't support asymmetric. I would expect to lose dual channel support, which reduces performance to some extend, but it shouldn't reduce capacity.

 

1 hour ago, iMxmo said:

Task manager readout here: (Shows 8Gb being recognized, but only 3Gb memory usage..?)

If you look in the lower right hand corner, you can see that task manager shows 5 GB as "hardware reserved". There are a number of possible causes. If you search the forum, you should find several threads about it.

• Memory limited in msconfig.exe > Boot > Advanced options... > [x] Maximum memory
• Memory sticks not making proper contact
• Broken memory module(s)
• Broken memory controller on the CPU
• Broken slot on the motherboard
• (and probably some others)

Though I would expect hardware issues to affect whole memory sticks, so you'd lose 2 or 4 GB and not such an odd amount.

 

32 bit Windows is also a distinct possibility. A 32 bit OS/CPU can technically address "up to" 4 GB of memory. But some of those 2³² memory addresses are needed for other stuff (e.g. hardware devices like the GPU), so in practice you'll always get a maximum value below 4 GB.

 

Maybe your buddy can use CPU-Z to identify the mainboard. If you know the mainboard model, it should be possible to find a manual online. The manual typically includes information about which slots to use given 1, 2, 3... memory sticks. CPU-Z can also show whether the memory is running in single or dual channel configuration.

[iMxmo]

1 hour ago, Eigenvektor said:

The system should still be able to use all of the memory even if the CPU/board doesn't support asymmetric. I would expect to lose dual channel support, which reduces performance to some extend, but it shouldn't reduce capacity.

 

If you look in the lower right hand corner, you can see that task manager shows 5 GB as "hardware reserved". There are a number of possible causes. If you search the forum, you should find several threads about it.

• Memory limited in msconfig.exe > Boot > Advanced options... > [x] Maximum memory
• Memory sticks not making proper contact
• Broken memory module(s)
• Broken memory controller on the CPU
• Broken slot on the motherboard
• (and probably some others)

Though I would expect hardware issues to affect whole memory sticks, so you'd lose 2 or 4 GB and not such an odd amount.

 

32 bit Windows is also a distinct possibility. A 32 bit OS/CPU can technically address "up to" 4 GB of memory. But some of those 2³² memory addresses are needed for other stuff (e.g. hardware devices like the GPU), so in practice you'll always get a maximum value below 4 GB.

 

Maybe your buddy can use CPU-Z to identify the mainboard. If you know the mainboard model, it should be possible to find a manual online. The manual typically includes information about which slots to use given 1, 2, 3... memory sticks. CPU-Z can also show whether the memory is running in single or dual channel configuration.

Thanks for the response. Yes we have CPU-Z downloaded atm. Just disappeared to Narnia for now. This situation really is tricky. I will look into the memory reserved causes you mentioned. I'll also look for the mainboard name, hopefully it'll give us a clue to some 'official' three DIMM layouts. All such a mess. Note: When in original config 1x2 in Slot 1. Slot 2 Empty, Slot 3 2Gb, Slot 4 4Gb. DIMMs were reported as single channel. I do have SS of each DIMM in CPU-Z if needed.