ciao

Computer RAM is, in fact, measured in MB/s not Mb/s. Would it make much sense to have the PCI-E bus run over 10x faster than the system RAM? What good would it be to transfer data 10x faster than receiving it?

So PC3200 RAM has a theoretical bandwidth of 3200MB/s (3.2GB/s) or 25,600Mb/s (25.6Gb/s). The number after the ‘PC’ tells bandwidth in MB/s. This makes more sense if the PCI-E x16 can do about 38,00Mb/s which translates to 4,800MB/s.

This further increases the gap between HDs and RAM. There is a much bigger difference between 3,200 MB/s RAM and 150 MB/s HDs.

I just needed to clarify your clarification.

8GB (max) HyperDrive IV £399 (+ PP and VAT) $698.25 (+ PP and VAT)

16GB (max) HyperDrive IV £599 (+ PP and VAT) $1048.25 (+ PP and VAT)

http://www.hyperossystems.co.uk/07042003/products.htm#hyperosHDIIproduct

I installed the board in my DFI Lanparty NF3 machine, and found that Windows crashed hard when I tried to create a partition.. I tried it in my DFI Lanparty NF4 machine. Same result. I tried it in my MSI Neo-4 NF4 machine. Same result on the Nvidia NF4 SATA ports, but it worked on the Silicon Image Raid-5 SATA ports. Hmmmm. I formatted a drive, copied files to it, and verified them — it worked fine. Then I moved the cable back to the Nvidia SATA port, and it corrupted the files.

I looked in the (slim) manual, and found a list of validated controlers. No Nvidia SATA controler is listed. They’re not supported. This is a serious shortcoming from Gigabyte. On seven computers I have only one non-Nvidia SATA port, and it’s not on my SQL server where I wanted to test the iRam. This basically made the iRam useless to me, and I dropped the project.

Maybe I’ll try again in the future, if Gigabyte improves their product. I was hoping for better.

Stammy: interesting and helpful bit, thanks

Obviously, closest to the CPU is your Level 1, and Level 2 cache. Next comes system RAM. DDR400 = PC3200. That’s 3200mbps, or twice that with a dual channel controller. DDR2 RAM is faster, but adds a lot of latency — pretty much a wash. On Intel chips, this data must also pass through the FSB channel, which runs at the same speed as the RAM.

Next in line is your AGP or PCI-Express channel. Each PCI-E 1x channel is about 2400mbps. A 4x slot could handle 10Gbps ethernet. Your 16x video slot is nothing short of amazing. These channels are on the motherboard chipset, so they also pass through the bridge to the CPU — either the AMD HyperTransport channel, or the Intel FSB (as does everything below this).

Next comes your IDE channel. Modern parallel ATA channels run at 100MB/s or 133MB/s. Note that we’ve switched from megabits/s to MegaBytes/s. Your typical HD can read 30-50MB/s. You can RAID them to get more throughput (provided you put each drive on a separate channel), but the latency is not increased by RAID. HD latency is a function of spin rate and head seek time.

Your Serial ATA channels can be either 150MB/s, or 300MB/s for SATA2. A 10k rpm Raptor can hit 70MB/s, so it doesn’t come close to saturating the SATA channel. The real value in the Raptor is low latency.

Next down the line is your high speed serial I/O, such as USB2, FireWire, or USB1. USB2=480mbps and Firewire=400mbps. That bits again, we we’re talking maybe 50MB/s max theoretical (30MB/s realistic). Gigabit Ethernet is faster. You can actually get 60-70MB/s transfer over the 1000mbps theoretical Gigabit port. On all of these, remember that the bandwidth is shared among all devices on the bus.

Anything on your PCI bus is slower than the above, and also shares bandwidth with all other PCI cards.

The Gigabyte i-RAM attaches to your 150MB/s SATA1 channel. It can actually transfer 135MB/s (~1000mbps). So it is limited by the SATA channel, and is at least 3-6x slower than system RAM. It is also at least 2x faster than a Raptor in bandwidth, and about 1000x faster in latency. You could double the speed and size by using RAID0.

As for what to use it for, the answer is to use it’s major strength: low latency. I plan to use mine (on order) in a local SQL server that I use for development. Obviously, the first thing to do is to max out the system RAM. But since this is a desktop motherboard (not a server motherboard) it holds only 4MB RAM, of which Windows will only let you use 2 or 3Gb. My i-RAM will be used to hold the indexes to database tables. These are small enough to fit, and will benefit from the zero seek time.

The i-RAM could be a better product. It really needs SATA2. It could also take 8GB RAM, fit in a 5.25 drive bay, and allow ECS memory. But all those things would increase the price. In fact, you can get all those things in other products for about $700. No thanks.

The real downside to the i-RAM is the cost, and that you cannot trust it. Your HD does CRC checking when reading sectors. The i-RAM does not, and DDR RAM is subject to soft errors. Also, a day-long power outage (unlikely as that is) will lose all your data. So you *cannot* simply use it to store a database. I plan to use mine for files that can be rebuilt on-the-fly from HD files.

Clearly, the i-RAM is not a product for everyone. A better product would be a 4GB caching SATA2 controller that would go in a PCI-express slot. Anyone know where to get one??

I am thinking about doing this with an fast external hard drive for my laptop through my firewire connection or changing out the internal HD and use an external for most of my programs.

Of course, I wonder if there will be noticable difference in hosting and serving say “Battlefield 2″ or other top of the line PC games through the internet or wireless connection in either scenerio. Is the iRAM more efficient to use rather than devoting one of the fastest hard drives on the market? Of course you should be able to match speeds with the processor as it works together.

Just a little ignorant (ok, hate to admit it but, well, maybe a lot ignorant)

Don’t put your temp file on the USB flash stick.

1st- you will burn your flash memory. The flash memory only supports a very limited number of writes (depending on the chip quality it can go up to 25 000 or 100 000 writes).
2nd – as the others have pointed out, your hd is probably faster than the flash memory on the USB stick.

If you’re on a laptop that means your hd is painfully slow. That is, for power consumption reasons + heat dissipation constraints, the hd in a laptop runs at 4200 rpm or 5400 rpm at best. Compared with 7500 rpm on a desktop hd, that’s at least 30% slower.

Instead you could get a ramdisk driver and set up a drive for your temp, teporary internet files, ie history, etc.
See http://users.compaqnet.be/cn021945/RAMDisk/ramdriv.htm, the free one should be enough for basic needs.

The speed of your IE with your history and temporary IE files on it will double easily.

It won’t increase performance because instead of writing to the USB drive you could be writing to the HD, which is faster than the USB drive.

USB 2.0 bandwidth is limited to 480Mbit/s or 60Mb/s. Your laptop hard drive is probably Ultra/ATA 133 which has a bandwidth of 133Mb/s. Discounting seek times (which may or may not be faster for your USB stick…but chances are they won’t matter since HD seek times are on the order of 5 milliseconds these days), you aren’t going to get any improvement from running on a USB stick.

And Christos is right – CPU/memory busses are on the order of 10,000Mb/s for newer models (Athlon 64 FX hits 12800) while SATA runs at 150Mb/s. And doesn’t really even reach that usually. That being said, I think you’d only ever use one of these things in a computer where you can afford to run the i-RAM as your OS HD and use your main memory for as application memory. This isn’t the kind of thing the casual user is probably going to buy… at least not for a long long time.

I’m planning a test with this kind of configuration but using an USB stick instead. I need increased performance in my laptop (Sony Vaio S2XP).