Reviews - AMD brings full force of Phenom II to bear with AM3 chips

[HEXUS]

But is the Force strong in AMD?

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[aidanjt]

I still don't see DDR3 as being a viable alternative tbh, DDR2 is much cheaper and can still hold its own, particularly if like the majority of apps you don't need to move around gigantic blocks of memory at a time. The main thing that gives i7 an edge is triple channel memory. But technically, you could adopt a DDR2 memory controller to support an extra channel of memory and get the same performance boost for less.

[kalniel]

I still don't see DDR3 as being a viable alternative tbh, DDR2 is much cheaper and can still hold its own, particularly if like the majority of apps you don't need to move around gigantic blocks of memory at a time. The main thing that gives i7 an edge is triple channel memory. But technically, you could adopt a DDR2 memory controller to support an extra channel of memory and get the same performance boost for less.

It's future proofing - DDR2 won't be much cheaper by the end of the year.

[aidanjt]

DDR2 won't be much cheaper by the end of the year.

That's true. But not due to any technological advantage. Anyway, you should know as well as anyone that 'future proof' and computing is both an oxymoron and buzz. You can grab 8GB today for next to nothing and it'll last you years.

[Funkstar]

That's true. But not due to any technological advantage.

Thats the same at the start of any new hardware generation. The benefits of first lot of hardware is negligible compared to the very top of the current generation.

DDR2 has been around for almost 6 years now, so it has had that amout of time to almost triple its performance and massively reduce its cost. Obviously manufacturers are reaching the limit of what DDR2 can do, DDR3 will be able to scale much higher than that, which is needed for it to last for another 6 years.

From Wikipedia: (http://en.wikipedia.org/wiki/DDR3_SDRAM)

Advantages compared to DDR2

• Higher bandwidth performance, effectively up to 1600 MHz
• Improved latencies as measured in nanoseconds.
• Higher performance at low power (longer battery life in laptops)
• Enhanced low power features

Disadvantages compared to DDR2

• Incompatible with DDR2 motherboards
• As of January 2009, costs somewhat more than equivalent DDR2 memory

[kalniel]

That's true. But not due to any technological advantage. Anyway, you should know as well as anyone that 'future proof' and computing is both an oxymoron and buzz. You can grab 8GB today for next to nothing and it'll last you years.

So you wouldn't mind purchasing a skt 939 CPU that's tied to DDR memory then? At the time of AM2 the same thing was said: no performance gain over DDR (infact, there was a performance loss), but now (or at any time in the last couple of years) would you rather buy more expensive, more power hungry DDR over DDR2?

[aidanjt]

So you wouldn't mind purchasing a skt 939 CPU that's tied to DDR memory then? At the time of AM2 the same thing was said: no performance gain over DDR (infact, there was a performance loss), but now (or at any time in the last couple of years) would you rather buy more expensive, more power hungry DDR over DDR2?

Yes, *eventually* DDR3 will be cheaper and faster and use less power over DDR2. But at present it isn't. Buying for tomorrow rarely means saving money tomorrow, especially in computing.

[MadduckUK]

Yes, *eventually* DDR3 will be cheaper and faster and use less power over DDR2. But at present it isn't. Buying for tomorrow rarely means saving money tomorrow, especially in computing.

i believe that is why you slot your nice new AM3 processor into a AM2+ mobo, congratulations, you have upgraded! - until such time as you feel ddr3 is viable, when you upgrade the mobo and ram - congratulations, you have upgraded again!

what's wrong with that?

[GaryRW]

For my build last year, I bought a gigabyte board that supports both DDR2 and DDR3. I wasn't really expecting they'll be any major performance boost if and when I upgrade to DDR3, but the board was only a couple of quid more than the equivalent gigabyte board that didn't support DDR3.

My main reason was that it will allow me to do any future upgrade one bit at a time - I don't upgrade that often, and was left with a socket 478 board, with only support for AGP and DDR. Hence a complete new build.

Here though, seems you're taking a bigger hit for the "future proofing" than the couple of quid I spent.

[scaryjim]

Here though, seems you're taking a bigger hit for the "future proofing" than the couple of quid I spent.

I guess that depends on whether you're already an AMD-user or not. If not then obviously you're going to take a bigger hit, because you'll have to replace your entire system. But if you're already running AM2(+), AM3 gives you a drop-in processor upgrade. And assuming that AM3 CPUs are backward-compatible to all AM2 motherboards, you could be upgrading PCs pushing 3 years old just by dropping in a new CPU and adding some more memory - and the CPU becomes the core of your next system, when you decide to upgrade to DDR3 (and, of course, if you keep that old processor safe you can drop it back in and sell the old subsystem to raise money towards the new one ). It's a way of spreading the cost but also getting benefit in between.

You just can't do that with Intel's processors - they won't keep making socket 775 processors for ever, and then you'll have to choose between i5 and i7 without being able to switch between them because they have fundamentally different macro-architectures. Once you pick your socket you'll have to get a whole new system if you want to switch.

My only real worry is this whole 1 stick of DDR3 per channel business. If nothing else, surely that will put people off going AM3 for a while...

[kalniel]

My only real worry is this whole 1 stick of DDR3 per channel business. If nothing else, surely that will put people off going AM3 for a while...

The what business? Never heard that before. So all these boards with 4 slots are quad channel?

[MadduckUK]

One thing about DDR3-1333 - the integrated memory controller on current AM3 processors only support a single DDR3-1333 DIMM per channel, thus limiting the amount of DDR3 memory that can feasibly be installed (good luck finding a 4GB DDR3 module now), even if the CPU does support up to 8GB memory on paper. At the moment, fully populating all the available DDR3 DIMM slots, assuming the typical 4 DIMMs, will result in a lower (than DDR3-1333) memory frequency.

i think this has been written pretty ****ty though

[kalniel]

So actually that's nothing to do with channels, but the rather more common fact that populating four banks leads to a reduction in working frequency and/or timings, just as it did for socket 939 boards?

[scaryjim]

So actually that's nothing to do with channels, but the rather more common fact that populating four banks leads to a reduction in working frequency and/or timings, just as it did for socket 939 boards?

So you're fine with 4 sticks of DDR3 1066, but if you put in 4 DDR3-1333 they'll automatically clock down to 1066? Doesn't that kind of defeat the object?

And is that something AMD are likely to be able to remedy in a future stepping?

[kalniel]

So you're fine with 4 sticks of DDR3 1066, but if you put in 4 DDR3-1333 they'll automatically clock down to 1066? Doesn't that kind of defeat the object?

Well, it's been that way for ages for some AMD chips/ets. It's not great, but it's not new.

And is that something AMD are likely to be able to remedy in a future stepping?

Yes, or new model.

[scaryjim]

Thanks! I'd not heard about those problems before (probably because I hadn't built any systems between Socket A and AM2!!) and the article doesn't make it very clear...

Sounds like I might be waiting a bit longer before I go new system shopping then... *sigh*