Investigating Intel's Turbo Memory: Does it really work?
by Anand Lal Shimpi on June 19, 2007 3:39 PM EST- Posted in
- Laptops
Understanding Turbo Memory: It isn't as clear as you'd think
Before we can accurately gauge the effectiveness or ineffectiveness of Intel's Turbo Memory, we have to be sure we understand exactly what it is supposed to do. Intel's Turbo Memory is on-motherboard flash split into two partitions: one for ReadyDrive and one for ReadyBoost. Turbo Memory is offered in two flavors, 1GB and 512MB, with 512MB and 256MB partitions respectively.
The ReadyDrive portion of Turbo Memory is designed to work with Vista's ReadyDrive technology. ReadyDrive's fundamental goal is to cache data from the hard disk to either improve performance or in the case of a notebook, improve battery life. The primary role of ReadyDrive with Turbo Memory in a notebook, is to increase battery life.
ReadyDrive can increase battery life by fulfilling data request out of low power flash memory, and keeping the hard disk spun down when not needed. If enough data is stored in the ReadyDrive partition of Intel's Turbo Memory, the hard drive can remain spun down for significant periods of time, thereby improving overall battery life. Obviously the success of ReadyDrive depends on its ability to correctly prefetch the right data into Turbo Memory's cache, but if it works, the battery savings could be significant.
The hard drive in our test system is a Hitachi Travelstar 7K100, which draws anywhere from 0.9W to 1.2W on average when simply spinning and not accessing data. In its lowest power mode, the 7K100 draws only 0.2W, so if we can keep the drive spun down the total system power savings are in the 0.7W - 1W range. If the drive is seeking for data, power consumption is almost 3W, and actually reading data off of the drive eats up 2.3W. If the data can be instead read from low power flash memory, the power savings could be tremendous.
Intel once stated that every watt of system power you can shave off can net as much as 20 - 30 extra minutes of battery life, meaning ReadyDrive with Turbo Memory can yield a measurable increase in battery life. The reality is that 512MB of flash memory isn't enough to keep the hard drive spun down 100% of the time, so the real question is how much of an impact will there be under real world usage? We'll be answering that question shortly, but now let's look at what Turbo Memory intends to do for ReadyBoost.
Taken from our Windows Vista Performance Guide:
ReadyBoost functions as a compliment to SuperFetch, giving SuperFetch another place to cache data that - while not as good as RAM - is better than just reading data off of the hard drive. An important distinction however is that while RAM is both quick to access and has high transfer rates, flash memory only offers quick access times, with transfer rates below that of even hard drives. As a result ReadyBoost is only useful in situations where small random data accesses are required, whereas larger transfers that may need sequential access are sent directly to the hard drive. This makes ReadyBoost less readily beneficial than SuperFetch, but with USB flash drives going for under $20/gigabyte, it's a cheap and effective way to boost performance of RAM-limited computers in a number of situations.
ReadyBoost also serves as a read cache of the system pagefile, with the idea that swapping to disk is less painful if it's done to a USB flash drive. Don't worry about sensitive data being kept and lost on your USB drive though; the data is compressed and encrypted so that it should be fairly useless once the drive is removed from use.
The point of ReadyBoost is to make things faster when you run out of memory, but is Turbo Memory any faster/better than simply using an external USB drive? The one advantage Turbo Memory has for ReadyBoost over an external USB drive is that the data stored in the ReadyBoost partition remains persistent through hibernation. In a normal system with a USB drive being used for ReadyBoost, if you hibernate the machine, the ReadyBoost data on the USB drive is invalidated because the USB drive could have been removed/tampered with and Vista can no longer count on the integrity of that data. Turbo Memory does not have that problem as the flash is on the motherboard and can't easily be removed on the fly, thus Vista will keep ReadyBoost data persistent in its flash when coming out of hibernate. The benefit being that any data cached via ReadyBoost will be accessible coming out of hibernate, which simply isn't true when not using Turbo Memory. This is the only advantage of Turbo Memory with respect to ReadyBoost, and understanding that will help you understand when/where it will make an impact on system usage.
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casket - Wednesday, June 20, 2007 - link
"If you add more memory to laptop, you use more power, emit more heat, etc"-- Using this logic... adding ReadyBoost (which is memory) would also use more power, emit more heat, etc...
The key here is that either readyboost or memory uses less power than a spinning hard drive. I would suspect you get the same power savings with more memory as well.
yyrkoon - Wednesday, June 20, 2007 - link
I dont know about anyone else, but I am starting to resent Intel using town names of the area I grew up in as a kid. You would think they could be a little more original.PrinceGaz - Wednesday, June 20, 2007 - link
I'd say that if it reboots every 6 minutes or so to re-run the test, it isn't worth a look and is totally useless as a notebook baterry-life benchmark as it in now ay reflects real-world usage, and all results using it should be discarded. Surely a better benchmark could be found than that. Unfortunately, removing the WorldBench results make Turbo Memory seem next to useless, which is understandable as it is likely to have been mainly the reduced HD activity when rebooting that the Turbo Memory was helping with.
JarredWalton - Wednesday, June 20, 2007 - link
And yet, the mocked up WorldBench 6 test shows a rather impressive 12% increase in battery life. It seems that the startup/shutdown process at the very least gets a decent benefit (in terms of battery life) from Turbo Memory. That indicates that the power savings from putting the hard drive to sleep are definitely tangible.redly1 - Wednesday, June 20, 2007 - link
I would like to buy this and test it out with my tablet PC. Anyone know where I can buy one of these mini-PCIe cards?skaaman - Monday, June 25, 2007 - link
Here is the part# NVCPEMWR001G110You can pick them up for under $35
BD2003 - Wednesday, June 20, 2007 - link
The problem I have with the article is that in general, they are still running benchmarks that do not reflect how an actual user interacts with their laptop, and do not really reflect the benefits that turbo memory/readydrive/readyboost would have.PCMark is supposed to give a number as to how fast your computer can run a barrage of application tests - but looping it over and over does not even come close to reflecting an actual usage pattern.
Now granted, they need a *repeatable* test to have numbers that are comparable, but that does not necessarily speak of the validity of the numbers.
For the average office laptop, you'll be running outlook, word, excel etc - the amount of data actually being loaded and saved is VERY small vs. large amounts from a benchmark, and in that very common scenario, the drive would rarely have to spin up, and the battery savings would probably be much closer to the ideal of 30 mins than what their benches showed.
I do agree with them on their final conclusion - 1gb is just not enough for more than basic office tasks. In order for this to really take off, to be able to cache an entire movie, they're going to need cache on the order of 4gb. Then I think it'll really make a difference battery/performance wise.
And they really, really need to fix the driver issues.
BikeDude - Wednesday, June 20, 2007 - link
If the movie is 4GB, a 1GB cache means (ideally) you will spin up the hard drive four times to load the next GB. I doubt you'll see much benefit from a 4GB cache in such a scenario.That said, the test didn't do any read ahead tests. All the descriptions so far seem to say the technology caches stuff already read. I.e. if streaming a movie from the hard disk there's nothing that will suck it all into a cache... (grrrr, this reminds me that my Hauppague TV tuner streams everything to a 7MB file which it then plays back -- works fine as long as I don't hit the same drive with heavy IO)
sorr - Wednesday, June 20, 2007 - link
i'd just use another Gigabyte of memory i.e, 2 GB in total and hybrid drive for now, then after 2~3 years just use the SSD when it comes down in price and goes up in capacitySilthDraeth - Wednesday, June 20, 2007 - link
Page 4 mentions Windows XP. I thought I read the article, but maybe I am missing something. I thought it was purely for Vista, but XP is mentioned several times.Please explain, because I am confused. Thanks.