"amd" ddr2...

[eccerr0r]

So what's with the "AMD" DDR2?

My (Intel) board "officially" supports 4G DDR2's (four slots, 16G total) but this "AMD" deal is kind of scary recalling back to the old SDRAM deal. In fact I have a few 512M SDRAM modules now but they don't work in my 440BX board, which is too bad, would rather run this board with 2GB RAM through its four slots, else have to use the VIA boards with only 3 slots is the best I can otherwise do.

But anyway I heard these "AMD" DDR2 still "work" on an Intel board but cannot clock at PC6400 speeds if it comes labeled as such, and must underclock and run at PC5300 speeds... but is that all?

Really should look into getting 8GB DDR3's instead of dumping more into DDR2...

[Uranium-235]

Re: "amd" ddr2...

They have special timings for AMD IMC's, but will work in intel just fine, speeds might have to be set manually

I think AM2+ can use 4gb sticks

[lti]

Re: "amd" ddr2...

I saw some really goofy modules with recycled (and overclocked, but that isn't unusual today - look at modern DDR4 "gamer" RAM) chips in a configuration that Intel's memory controllers didn't support.

[eccerr0r]

Re: "amd" ddr2...

I was thinking about ripping up old modules and sticking more chips on unused double sided boards but finding equivalent chips is kind of tough.

But the weird thing is that some of these 4G modules look legitimate... 32-chip modules, 2x8=16 on a side, samsung, hynix ?

[RJARRRPCGP]

Re: "amd" ddr2...

but cannot clock at PC6400 speeds if it comes labeled as such, and must underclock and run at PC5300 speeds...

That's 99 percent true, if using 4 sticks and you likely need 1.90 V for VDIMM with 4 slots.

So what's with the "AMD" DDR2?

Welcome to the IMC days, where the compatibility is mostly determined by the CPU chip, per-se!

[eccerr0r]

Re: "amd" ddr2...

DDR2 predates IMC however, or did AMD design around DDR2 that doesn't quite fit JEDEC specs?

[RJARRRPCGP]

Re: "amd" ddr2...

DDR2 predates IMC however, or did AMD design around DDR2 that doesn't quite fit JEDEC specs?

True, in the case of Intel, where they clearly stuck to FSB until at least socket 1366 and socket 1156, IIRC.

[ratdude747]

Re: "amd" ddr2...

True, in the case of Intel, where they clearly stuck to FSB until at least socket 1366 and socket 1156, IIRC.

Nope. The last FSB sockets were 771 and 775. Nehalem and later uses IMC (to include DMI-based LGA1156).

[Topcat]

Re: "amd" ddr2...

With the exception of soDIMM's, I don't think I've ever seen a PC2-5300 or 6400 that was non-ECC/non-FB/unregistered larger than 2gb.

[Uranium-235]

Re: "amd" ddr2...

Nope. The last FSB sockets were 771 and 775. Nehalem and later uses IMC (to include DMI-based LGA1156).

yeah triple channel imc. Was kind of impressive for the time for retail. I had a 920. Still have. It's my shop box

AMD's first IMC's since s754 around 2003, far before 1366

With the exception of soDIMM's, I don't think I've ever seen a PC2-5300 or 6400 that was non-ECC/non-FB/unregistered larger than 2gb.

I've seen tons of them. 533, 667, 800, SO-dimms, regular dimms, Ecc, Registered, though i've seen few FB's over 667. It's easier to make 4gb and higher sticks with registered obviously.

AM2+ in particular can take 4gb sticks

[piernov]

Re: "amd" ddr2...

DDR2 AMD only RAM is a thing because Intel had one less (column) address bit available on their memory controllers, so depending on the memory organization some sticks aren't compatible with Intel platforms.
The well-known RAM stick manufacturers very rarely used these chips, probably to avoid confusion with the end-user, but it seems like the sellers on Aliexpress got a hold of these (probably used) chips and are selling sticks with them cheaper than the "Intel-compatible" ones.
You can look for the datasheet of the RAM chips to see what the memory organization is.

I'm not sure about DDR3, but I remember that in the early days sticks were mainly 1.8V instead of 1.5V, and people were saying that it is an issue with (DDR3-only) Intel's Integrated Memory Controller, Intel specifications were only for 1.5V DDR3.
AMD AM3 CPUs still supported DDR2 that typically ran at 1.8V so it may be the reason why it wasn't seen as a problem for AMD.

I did confirm myself that both AMD-only DDR2 and DDR3 won't work in an Intel platform. So there may also be an issue similar to DDR2 addressing with DDR3 on Intel.

[Topcat]

Re: "amd" ddr2...

533, 667, 800, SO-dimms, regular dimms, Ecc, Registered, though i've seen few FB's over 667. It's easier to make 4gb and higher sticks with registered obviously.

Just as I said....except the "regular DIMM's" part... Feel free to link me to some regular 4gb PC2-6400 DIMM's; unbuffered, non-ECC, unregistered. I have plenty of the rest, up to 8gb/module for the workstation/server stuff (FB, ECC/Reg)....but 'regular' ones for consumer level stuff, 2gb seems to be the biggest I can find.

[zunasthegreat]

Re: "amd" ddr2...

So what's with the "AMD" DDR2?

My (Intel) board "officially" supports 4G DDR2's (four slots, 16G total) but this "AMD" deal is kind of scary recalling back to the old SDRAM deal. In fact I have a few 512M SDRAM modules now but they don't work in my 440BX board, which is too bad, would rather run this board with 2GB RAM through its four slots, else have to use the VIA boards with only 3 slots is the best I can otherwise do.

But anyway I heard these "AMD" DDR2 still "work" on an Intel board but cannot clock at PC6400 speeds if it comes labeled as such, and must underclock and run at PC5300 speeds... but is that all?

Really should look into getting 8GB DDR3's instead of dumping more into DDR2...

I have such dimms (2x4GB AMD DDR2), those dimms use different chips/arrangment/rows "256Mx4" that have issues/incombatible with the intel memory controller design. I have tested the memories on intel P35 and the board only read them as 2GB dimms. Other users said that these memories work fine on nVidia s775 chipsets. It was meant as a cheap DDR2 alternative for AM2 platform.

[Uranium-235]

Re: "amd" ddr2...

I have such dimms (2x4GB AMD DDR2), those dimms use different chips/arrangment/rows "256Mx4" that have issues/incombatible with the intel memory controller design. I have tested the memories on intel P35 and the board only read them as 2GB dimms. Other users said that these memories work fine on nVidia s775 chipsets. It was meant as a cheap DDR2 alternative for AM2 platform.

The G41 intel chipset supports 4gb ddr2 sticks

[piernov]

Re: "amd" ddr2...

It's not an issue with the total memory capacity but an issue with the RAM chip organization. The "x4" chips transmit 4 bits at a time for a given memory address and have to use an additional column address bit to address the full memory that apparently Intel memory controllers don't support.
However it should not POST at all if you use this incompatible memory. (the SPD profile inside the stick should report the memory organization, and since the memory controller doesn't support it the BIOS should fail RAM initialization)

[Topcat]

Re: "amd" ddr2...

The G41 intel chipset supports 4gb ddr2 sticks

Many of those also support DDR3.

[eccerr0r]

Re: "amd" ddr2...

For SDRAM, my 440BX does not support "AMD" organization DIMMs. When I stick in "AMD" 512M SDRAM into it, it reports them as 128MB modules. Likewise for "AMD" 256M SDRAMs.

However my VIA boards happily recognize all 512M on these modules... one's an Athlon, other is a P3.

Seems like it's SDRAM funnybusiness once again in the DDR2 world?

[Topcat]

Re: "amd" ddr2...

For SDRAM, my 440BX does not support "AMD" organization DIMMs. When I stick in "AMD" 512M SDRAM into it, it reports them as 128MB modules. Likewise for "AMD" 256M SDRAMs.

However my VIA boards happily recognize all 512M on these modules... one's an Athlon, other is a P3.

Seems like it's SDRAM funnybusiness once again in the DDR2 world?

The BX chipset doesn't support 512mb modules as it is, it's a limitation within the chipset. It supports 256mb spanned over 4 slots for a max of 1gb. If you want 2gb RAM in that era of board, you need the GX chipset. There were a few slot-1 motherboards that sported this chipset for this reason....but most were slot-2.

[eccerr0r]

Re: "amd" ddr2...

One would expect 512M modules to show up as 256M if 256M is supported. But even certain 256M modules also show up as 128M modules, so all these modules show up as 128M instead of 0M and start beeping...

[RJARRRPCGP]

Re: "amd" ddr2...

Nope. The last FSB sockets were 771 and 775. Nehalem and later uses IMC (to include DMI-based LGA1156).

Yes, those were the last to use FSB. 1366 and 1156 marks the change to IMC, which AMD was doing at least since socket 940 (2003, albeit they still made socket 462 CPUs and that didn't stop until 2005-ish) and socket 754, IIRC.