The Essential Data Recovery ReportWritten by Greg Duffield
Your worst nightmare just became a horrifying reality. You keep hearing that little voice in your head mockingly shout “you should have backed that stuff up” The voice keeps echoing throughout your head as you perform a quick inventory all of important information that you just lost…..your client database, a years worth of e-mail, your entire inventory database, even your family photos. Even worse, you’ve got a deposition in two-weeks and key information needed to help win case were also lost. You quickly call a service technician and have them come over to check computer out, only to hear worst news of all….your data has been lost. When a hard drive crashes, it’s too late to worry about what you “should have done.”Today data recovery is a multi-million dollar industry. The number of data recovery firms out there seems to exceed number of fast food restaurants for entire planet. These companies specialize in helping their clients retrieve data on anything from hard drives to flash-roms. In following report, we will discuss what data recovery really is; different types, costs, and what you can realistically expect when it comes to getting your data recovered. What To Do In The Event Of Data Loss? Around 44% of all data loss is caused by hardware failure. It’s important to make sure that you immediately shut your system down if you suspect that hard drive has crashed. Don’t even try to go through shutdown procedure, just pull plug from wall. Do not try to run off shelf data recovery software or drive utilities. Many times these applications will assume drive is functioning properly and will increase risk of permanent data loss. Types Of Hard Drive Failure When we discuss data recovery in this report, we will primarily focus on issues surrounding hard drive failures; since these types of failures are most common. There are really two primary forms of failure in a hard drive, logical and physical. Logical failures are usually a result of file-system corruption. This can occur due to a virus, accidental deletion of key files or registry components, and in some cases even electro-static discharge. In most cases where a logical failure has occurred, drive is still recognized by system BIOS, but it will not boot. In most cases, your data should still be intact on drive, even though it may appear to be inaccessible. If system BIOS does not detect presence of hard drive, then chances are a physical failure has occurred. Physical failures can result from a wide variety of causes. There are really two sub-categories for physical hard drive failures; mechanical and electronic. Mechanical failures usually result from a failure of spindle motor. Spindle motor failure can result from excessive heat due to a bearing failure. The increased heat resulting from bearing failure will expand drive shaft and therefore seize spindle motor. Suddenly, your drive will become inoperative. Occasionally, you will get a warning that something bad is about to happen. You may hear a loud whining, a grinding noise, even high-pitched screeches. If anything like this starts to occur, BACK UP YOUR DATA IMMEDIATELY. Another physical issue that sometimes rears its ugly head is an electronic failure. If you look at a hard drive you will notice a circuit board on bottom. This board is basically brains of drive, and it is where computer interfaces to hard drive. An electrical failure can occur unexpectedly at any time. Even brand new hard drives are not totally immune to having electrical failures. Sometimes it’s just a faulty component, sometimes it’s improper installation (i.e. electro-static discharge, grounding out board, damaging circuitry during installation). It’s important to also keep your system clean and well ventilated, since excessive heat can damage electrical components on drive. If you have a system that is in a somewhat contained area, you may look at adding an additional 80mm fan to cool internal components of system, especially hard drive. No other component of a computer works as much as hard drive, and therefore it is vitally important not to overlook it when cooling issues arise. How Is My Data Recovered? One of most often asked questions that customers ask is, “how do you get my data back?” Well, it’s really not black magic or rocket science. It’s just a matter of having right tools and knowledge necessary to know what to do, much like a surgeon performing heart by-pass surgery. Many prominent data recovery facilities have a large array of hardware, software and tools for recovering data. Generally speaking when a hard drive is received by a data recovery firm, first thing they do is evaluate it, and determine what recovery solution will be necessary. If drive failure is a logical issue as mentioned earlier, then a scan of drive will be performed to try and repair file system corruption. Sometimes a partition can be repaired and drive restored to status that it was before failure. If this is not possible, then a very low-level scan will be performed that essentially searches every sector of hard drive for files. Once files are located, they can then be copied to media of choice, i.e. a CD-ROM, DVD-ROM or another hard drive. Logical recoveries can take up an enormous amount of time, especially if drive is on verge of physical failure. It’s not uncommon to allow for one day of scanning and a day for recovering found files. If drive has suffered a physical failure, then recovery procedure is quite a bit more challenging. As mentioned above, there are really two sub-categories of physical failure; mechanical and electronic. An important element in recovering data from a physical failure is having necessary parts to get drive functioning again. Unfortunately with hard drives if you have a 20GB Maxtor Hard Drive for example, then you will need another identical 20GB Maxtor Hard Drive for salvaging parts. In cases where electronic circuit board has failed on hard drive, then you have to have exact same circuit board on hand in order to retrieve necessary circuit components for replacement. Many times you cannot even exchange circuit board for circuit board. These repairs generally require soldering skills and a thorough knowledge of electronics to be successfully completed. You will most likely hear “Class100 Clean Room” thrown around a lot when talking to data recovery professionals. Simply stated, a Class100 Clean Room maintains exceptional air purity, and contains less than 100 airborne particles larger than 0.5 microns in each cubic foot of air. This is vital in protecting sensitive internal components of hard drives. Anytime a hard drive is having an invasive procedure performed on it, a Class100 clean room or better is needed.
| | Memory Bandwidth vs. Latency TimingsWritten by Ron Merts
Memory Bandwidth vs. Latency Timings All memory is not created equal, nowadays you need to know which 'flavor' is best for an Intel or AMD PC if you expect best performance back from your investment. When Intel released i865PE/i875P dual channel core logic alongside Intel Pentium 4C processors, memory game changed forever. With a DDR memory controller now capable of running dual channel, Pentium 4 was no longer to be bandwidth limited as it had been with i845 series. Those single channel DDR chipsets, like i845PE for instance, could only provide half bandwidth required by Pentium 4 processor due to its single channel memory controller. As new 800 MHz FSB Pentium 4 processors allowed users to hit never before seen highs in terms of bus speed, many memory manufacturers were trying to capitalize on situation by releasing every increasing degrees of "high speed" memory. Unfortunately, to run memory frequency at same speed as FSB (or a 1:1 ratio) almost all high speed DIMMs (Dual Inline Memory Module) have to have very lax timings. Often, these times are as low as 3-4-4-8! Think about it this way, a car built for drag racing can go dead straight super fast, but cannot maneuver as well as an F1 race car. Likewise, F1 racer is good in corners but will be left in dust on drag strip. In other words, today's high speed memory modules are built for one thing only, and that's top speed, where timings really aren't considered all that much. Memory timings play a key role in terms of overall system performance. More so in 3D based applications which do not need a great deal of bandwidth, but rather quick access between various pieces of hardware within computer. Confused about memory timings? When one talks about memory timings they're basically talking about how long system has to wait for memory to be in a ready state before data is fetched or delivered. You could think about memory timings as people working at a drive through restaurant; you place your order then wait for food to be ready. The lower timings are, faster computer (and quicker your order comes) is able to get data from memory, and faster rest of PC will ultimately be. This rule of thumb applies whether you're on an Intel or AMD based system. As for why there aren't lower timings then 2-2-2-5, JEDEC (the memory governing body) does not think it's possible for current dynamic memory technology to run at 0 or 1. When we refer to timings it is common to quote a four digit number separated by dashes (ie. 2-2-2-5). The first number always represents CAS (Column Address Strobe) Latency as it's usually most important. Next in line is RAS-to-CAS Delay (Row Address Strobe), RAS Precharge and Act-to-Precharge Delay (which is always final, and largest number). CAS latency is delay between registration of a read command and availability of first piece of output data. CAS latency is measured in clock cycles. With all things equal, a stick of DDR memory capable of running 2-2-2-5 will make computer operating experience seem faster than a DIMM which may only run at 3-4-4-8. This is because delay from when memory receives an instruction, retrieves data, and sends it back out is less. Where it starts to get confusing is when you has choice of buying high speed memory with slow timings. Just about every PC3700+ rated memory module we've seen uses conservative timings after all. If your answer would be to buy fast memory with tight timings, I'm afraid you're going to be disappointed as there are no such modules available yet. So, why are we still interested in fast memory with slow timings then? Well, answer goes something like this.... Why release fast memory with slow timings? In highly competitive markets, once a major manufacturer releases a new and innovative product, rest will surely follow close behind. If one manufacturer doesn't follow suit, their products are considered 'old tech'.
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