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Discussion in 'MacBook Pro' started by kfscoll, Feb 27, 2011.
The i7-2820QM supports a 1600MHz memory speed...who's going to give it a shot?
this is about the ram right? sorry im a noob with computers and i registered here to learn.
P.S. can you please inform me what you do for a living? lol
Yep, it's about the RAM.
Presumably if the motherboard supported the higher speed RAM then they'd ship it, cost permitting. Might just be prohibitively expensive now, haven't checked. Could be tempted to try it once I upgrade!
Who's going to be the first to realize that the RAM multi is probably locked on these boards?
Not sure about that. Although a desktop chipset, the late-'09 iMacs shipped with 1066MHz memory but would recognize and properly run 1333MHz memory if it was installed. I'd imagine the MBPs would behave similarly if the chipset supports 1600MHz memory -- and since the CPU supports it, it'd be silly if the chipset didn't.
PC3 12800 memory isn't that expensive, it just doesn't seem that common. This is the only listing for it on Newegg and it's out of stock.
The Sandy Bridge architecture is very different in the way it deals with clock speeds.
I would try this right now if I had my MBP but it wont be here for a while since I have to get it shipped overseas. 8GB of DDR3 1600 is only 99 bucks. Thats awesome. Super Cheap.
I know for a fact that this ram works on other Sandy Bridge PCs since DDR3 1600 is supported, and I know for a fact that in previous Mac's that came with slower memory, you could use the faster memory that the CPU/Chipset supports no problem, and it would work at the rated speed.
So putting that logic together, the DDR3 1600 memory will operate at 1600.
Someone should try
What does that even mean? How is it different with respect to memory speed than the previous generation (X58 et al) platform?
iBunny, I read the data sheet on that Kingston memory and it seems that the SPDs are programmed to JEDEC standard latency DDR3-1333MHz timings. You'd need to be able to tell the MBP to read the XMP profile to get the memory to run at 1600MHz and I very seriously doubt it does that by default. In other words, I'd bet this memory will downclock to 1333MHz because it's almost a sure bet that the MBPs adhere to the standard JEDEC memory timings.
Yes, the HyperX memory, as I read it, is more for overclockers that have the ability to manually set the frequency.
I would have tried it, but alas the 13" i5/i7 only goes to 1333. So I'll just stick with the $20 cheaper 1333 memory.
Yup. Same here. I'll go with Crucial, Corsair, or Mushkin -- whichever is cheapest at the time.
If I had mine I'd buy the RAM and give it a shot. If it hasn't been done by the time I get my 15" I'll but 8GB and install it.
1600 memory will function just fine. There is no "chipset" in the traditional terms - the memory is connected directly to the processor now. The processor supports 1066, 1333 and 1600.
However, the higher frequency will increase heat and lower battery life. So I would bet that Apple has the EFI lock the upper limit of the memory to 1333.
I would be interested in seeing some memory benchmarks on this, if someone does try it out.
What's the point? All benchmarks show that RAM speeds shows little to no difference. It will only shorten battery life and cost money for practically nothing to gain.
Everything but the cheapest RAM is a waste of money. The only useful RAM upgrade IMO could be low voltage RAM with 1.2V instead of the usual 1.5V. No difference in speed but bettery battery life.
Isn't the memory connected directly to the processor in the X58/Nehalem line also? If so, I can tell you from experience it wasn't as simple as plugging in faster memory to get it to run at the higher speeds. I have some ultra-low latency RAM in my i7-965 PC and I had to tell the BIOS to use the XMP settings to get the memory to run with its rated low latencies since they weren't the "standard" JEDEC timings. I bet it's the same here -- although Macs don't have a BIOS, the EFI would still be required to use the XMP timings/speeds to run at 1600MHz, and I bet the EFI would automatically select 1333MHz JEDEC speeds.
I agree there's not much performance to be gained in going from 1333MHz to 1600MHz, but why not give it a shot if there's no additional cost? I just don't think it'd work, but I guess we won't know for sure until someone gives it a try.
You may be abel to use rEFIt to change the memory settings.
Memory clock is not nearly as important as timing.
As the manufacturers increase the clock speeds, the timings become slower. The actual performance difference is not going to be noticeable. The timing will become faster as they improve their manufacturing but it's not a priority for anyone.
I rather spend less money for faster timing and lower clock speeds.
Actually, no. Timings are much less an issue with newer ram standards. Back in the day, AMD systems were much more reliant on low timings over clock. With intel systems, and the speed and bandwidth of ram now, it's much less of an issue.
Show me some benchmarks.
Look at the last page of the conclusion, lower timing DDR3-1600 is better than higher timing DDR3-1600. It's no question.
Obviously lower timings are always better. The degree of reliance on timings for large performance boosts is very insignificant, however. (As you noted, a staggering difference of 1% performance)
And it's also performance that a person would only observe in synthetic benchmarks. You'll never notice any of this in actual usage.
I'm glad we agree on something.
My recommendation has always been buy RAM according to the DDR generation, don't let the clock speeds be the deciding factor. Find the best spec/price ratio and you should be fine.
Next week RAM prices will be lower, again. And you'll never truly futureproof yourself against Moore's Law. That's just the reality.
Strongly disagree. Dirt cheap RAM tends to have higher failure rates, which in turn leads to system instability and data corruption. Don't aim for the cheapest RAM out there.
This. And, the lower the voltage, the more unstable (at higher speeds).
Historically at least, apple laptops have only ever run at their stock meant for ram speed, so even if put in faster ram, it won't run faster. though you might get lower timings if its better stuff.