One of the frequent issues people reported with the Studio 1558 when it was released was overheating. Some configurations were on the edge of reliability, particularly with the thermal pads Dell used, which weren’t ideal for the higher-power CPUs. Dell made some changes in BIOS A04/A05 to improve thermal management somewhat, but those settings are not user-configurable in the stock BIOS. Combined with the direction of airflow and the difficulty in reaching the fan for cleaning, that meant that airflow could be restricted by the surface the computer was used on and large balls of dust could also build up between the fan and the radiator fins.

People came up with all sorts of solutions involving polishing the heatsink, using expensive heat sink paste and even copper shimming. One of the things people reported was that the fan would never run at full speed, even when the system was close to overheating. The only time it ran at full speed was while flashing the BIOS! I have also found that using the computer with the optional 9-cell battery helps, as the 9-cell version elevates the rear of the computer by around 1″, allowing unrestricted airflow into the bottom vent. With the standard battery, there is only 1/8″ or so between the bottom of the notebook and the surface it is sitting on. Of course, regardless of which battery is installed, it is important to not use this computer on a soft surface or anything else that might obstruct airflow.

Way back in 2011 a user named “kizwan” on the Notebook Review forum posted a modified A11 BIOS for the 1558 and subsequently updated it to the A12 BIOS per my request. It enables all of the submenus present in the Phoenix BIOS. Not all of those features apply to the Studio 1558 and as these menus were never enabled in the released BIOS, there are typos. For example, the “CPU Control Sub-menu / LPC Control Sub-menu” is completely empty and “Clarksfield” is mis-spelled “Clsrksfield” in at least one place. Also, some of the explanatory text for some menu items wraps around to the left side of the screen. None of these cosmetic issues in BIOS setup affect regular operation of the computer as they only appear in BIOS setup.

It is possible that changing some of the now-visible additional settings could put the 1558 into a non-bootable state. In that case, just disconnect the AC power adapter and the battery, then open the user access cover on the bottom of the 1558 and remove the CR2035 coin cell. Push the power button on the side of the computer to discharge any remaining “flea power” and clear the CMOS settings, then reinstall the coin cell, replace the user access cover and reconnect the battery and AC adapter. On power-up, the BIOS should report that the CMOS settings are invalid and let you enter BIOS Setup by pressing F2.

There is one known interaction which may or may not present a problem – if you enable “VT-d Technology” in the “CPU Control Sub-Menu”, the computer cannot boot from removable USB media. This is not limited to the Studio 1558 BIOS – a number of other systems from the same timeframe have reported similar problems.

Here is the menu with the various fan temperature thresholds. In this picture I have changed the defaults to turn the fan on earlier and faster:

I have been running this BIOS for nearly 10 years and have not had an overheating problem, including in Death Valley when it was 126° F and several weeks per year every year since 2015 in the Mojave Desert where the temperature was always over 100° F. I do disassemble the computer annually to clean out the dust from the fan as well as blowing the desert sand out of the keyboard.

In case the MediaFire page vanishes, I have saved a copy of the file here. You can verify that the MD5 checksum matches the one in the original Notebook Review post.

I’ve had a number of Dell Studio 1558 laptops for well over 10 years now. Occasionally people ask me “Why do you still have that old thing? You need a newer/faster/better system!” Actually, I don’t and I’m going to explain why.

The Studio 1558 (as I have configured or built them) has lots of still-relevant features, like:

• Quad-core i7-740QM CPU with Hyperthreading
• Discrete AMD HD5470 graphics
• 16GB of user-expandable memory instead of being soldered in
• Backlit keyboard with sculpted keys and 3 backlight intensity levels
• Full-HD (1920 x 1080) screen w/ matte (anti-glare) finish
• 1TB Samsung 860 EVO SSD
• 6x Blu-ray recorder
• Integrated 802.11a/b/g/n/ac/ax WiFi using Alfa AWPCIE-AX200U (based on Intel AX200) card
• Integrated Bluetooth 5.1 (included with AWPCIE-AX200U)
• Integrated 4G LTE universal mobile broadband using Dell DW5808 card
• Integrated GPS (included with mobile broadband)
• Built-in SDHC card reader
• Built-in hardwired Gigabit Ethernet
• 9-cell battery for extended runtime
• Readily available schematics, service information and parts
• Very attractive (IMHO) styling

However, being an 11 year old design, it does have some limitations. In approximate order from most annoying (to me) to least annoying:

• Limited to 8GB RAM (not really – see my other blog post here)
• Somewhat lower CPU/memory performance (see below)
• Lower-end graphics performance for a modern laptop (see below)
• SATA 2 interface for disk drive and optical drive
• USB is 2.0, not a newer specification
• “Gigabit” Ethernet tops out at around 600Mbit/sec
• The last officially-supported operating system was Windows 7 (but it can run Windows 10 – see my other blog post here)

I don’t use this laptop for gaming, so the graphics performance isn’t a problem. I do some very light Photoshop editing when I’m on the road and posting pictures. The SATA 2 interface isn’t really limiting since I have a Samsung 860 EVO SSD with Samsung Magician software which boosts the speed quite a bit. The only time I miss having USB 3 is when backing up pictures / videos I took while traveling to an external USB hard drive for safekeeping, and that can happen overnight while I’m sleeping.

I’m going to compare the Studio 1558 with the closest-to-equivalent current systems from Dell.

First, let’s consider a Precision 7550 high-end workstation-class system configured as closely as possible to the specs of my Studio 1558 (PDF of Precision configuration here). That currently prices out at $3497.56 list price, $2439.33 sale price. While it has a faster CPU, memory and graphics, it has a keyboard with those annoying flat tops instead of sculpted ones like the ones on the Studio 1558. And it has no provision at all for an internal optical drive.

Next, let’s try a low-end system. Dell’s low-end systems are not customizable beyond selecting a stock hardware configuration with whatever software you want pre-installed. I selected the Inspiron 15 7000 as the model that came closest to the 1558 (PDF of Inspiron configuration here). After selecting 16GB RAM, 1TB SSD and a backlit keyboard, only one configuration remains, with a list price of $1659.99 and a sale price of $1409.99. Again, this has a faster CPU, memory and graphics but also the annoying flat-top keys and no internal optical drive. In addition, it lacks hardwired Ethernet (WiFi only), doesn’t support any mobile broadband options, offers no extended-runtime battery and probably has other drawbacks. It does have a higher-resolution screen than either the Studio 1558 or the Precision 7550 configuration shown above.

I’m picking Dell systems to compare with because they’re the ones I’m most familiar with, service manuals, parts and schematics are readily available, Dell doesn’t make you jump through hoops to prove you’re entitled to download drivers and BIOS updates, and doesn’t do silly things like having the BIOS only recognize officially “blessed” vendor-branded WiFi or other add-in cards. If you know of current non-Dell systems that are close to the Studio 1558’s configuration and reasonably priced, I’d like to hear about them in the comment section.

As far as performance of the Studio 1558, it is quite reasonable. Microsoft still includes the “winsat” benchmarking tool, though it no longer displays the scores on the Control Panel / System page. But if you know where to look:
%windir%\Performance\WinSAT\DataStore\* Formal.Assessment (Initial).WinSAT.xml
you can find the scores. Windows 10 rates the system on a scale of 1.0 through 9.9 instead of the 1.0 through 7.9 scale of Windows 7. Here are the results for one of my Studio 1558 systems running Windows 10:

Overall System Score: 5.1 (lowest of the following scores)
Memory Score: 8.5
CPU Score: 8.5
Graphics Score: 5.1
Disk Score: 7.75

For comparison, the scores on Windows 7 were:

Overall System Score: 5.7 (lowest of the following scores)
Memory Score: 7.7
CPU Score: 7.5
Graphics Score: 5.7
Gaming Score: 6.3 (no longer rated in Windows 10)
Disk Score: 5.9

That shows that a high-end configuration of a Studio 1558 makes a fine Windows 10 machine if you aren’t making extensive use of graphics. Just for comparison, this is the Windows 10 winsat result from a high-end (Precision 3630 with Xeon E-2286G CPU, 32GB 4-way interleaved RAM, Radeon Pro WX7100 graphics and a 1TB Class 60 NVME drive) workstation costing over $5000:

Overall System Score: 8.7 (lowest of the following scores)
Memory Score: 9.3
CPU Score: 9.3
Graphics Score: 8.7
Disk Score: 8.9

I’m happy with that.

Please note that the above benchmarks and my “seat of the pants” performance opinion is based on a system with an i740-QM CPU (this was the top-end CPU offered by Dell in the 1558), 8GB or 16GB of RAM, and a fast 1TB SSD running Windows 10 x64 LTSC. As part of the research for this article, I used a 1558 with an i5-520M CPU, 4GB of RAM and a 320GB mechanical hard drive, running Windows 10 Pro 20H2. Saying the overall experience was quite unpleasant would be a bit of an understatement. Simply restarting Windows had the disk saturated at 100% for well over 10 minutes as shown by the Task Manager / Performance window. A SSD would certainly have helped, but the 4GB RAM certainly caused a lot of paging activity. Given the cost of the upgrades today, it seems silly to not upgrade a Studio 1558 to a top-spec system.

With the computer running Windows 10 LTSC and Office 2019 Professional Plus, I felt it was only fitting to update the palmrest badges to reflect this. This is the original “Energy Star” sticker from 2010, but the CORE i7 badge has been updated to the latest style, the Windows 7 badge was replaced with a Windows 10 one, and an “Office 2019 Professional Plus” sticker was added to complete the display. The “Portable4” and “Backup PC” labels indicate the hostname on my network and that this is one of 3 identical Studio 1558 computers, one labeled “Real PC” that goes on the road with me when I travel, and 2 labeled “Backup PC” in case something happens to the real PC.

As part of an upgrade of my Dell Studio 1558 computers to Windows 10 (you can find all of my Studio 1558-related posts here), I decided to investigate the possibility of actually installing 16GB of RAM in each one. This is theoretically impossible according to Dell. So I checked the Intel Ark page for the Core™ i7-740QM CPU and it also says “Max Memory Size (dependent on memory type) 8 GB”. Pretty definitive, right?

Getting into the technical nitty-gritty, “Intel® Core™ i7-900 Mobile Processor Extreme Edition Series, Intel Core i7-800 and i7-700 Mobile Processor Series Datasheet – Volume One” (document number 320765-001, September 2009) is quite clear on pages 20-23 that the largest DIMM configuration supported is two 4GB modules. The “Intel® Core™ i7-900 Mobile Processor Extreme Edition Series, Intel® Core™ i7-800 and i7-700 Mobile Processor Series – Specification Update” (document number 320767-028US, February 2015) doesn’t say anything about support for increased memory sizes.

Not that that has ever stopped me before… I checked the Crucial web site (not that I’m a big fan of Micron/Crucial, but they are a memory chip manufacturer as well as selling memory modules) and they also list 8GB maximum memory, using 2 CT51264BF160B 4GB modules. This is a DDR3L-1600 part with 11-11-11 timing at that speed. That is a faster part than the Studio 1558 needs, since the fastest memory any of the CPUs in the 1558 need is DDR3-1333 with 9-9-9 timing. Fortunately, most things are perfectly happy with faster memory, even if they won’t make use of it. Cisco excepted, of course.

It turns out that Crucial makes that exact same spec of memory in an 8GB module, the CT102464BF160B. At only $37.95 each from Amazon, it seemed like a fun project to order two of these modules and see what would happen. And this was the result:

So far, so good. But what would the longer-term reliability be like when the system was heavily loaded? I decided to run Memtest86+ 4.20 (available here) to see:

At that point it had run solidly for 3 passes / 11 hours in Memtest86+. So I think it is safe to assume that this will work for the long term. This image also shows that the full 16GB is cacheable – sometimes when experimenting with oversized memory configurations only part of the memory is cacheable, leading to inexplicable random-seeming performance drops. Not shown in this picture, but displayed on another Memtest86+ screen, is that the memory is operating in fully interleaved mode, which Intel refers to in the datasheet as “Dual-Channel Symmetric Mode” which provides maximum performance. This is the same mode that 2 * 4GB memory operates as. so there is no performance loss with the larger memory.

Of course, Dell and Intel both saying that it is unsupported means that you’re doing this at your own risk. It is not like any of these notebooks or CPUs are still in production (or even under warranty) at this point, 10+ years later. IMPORTANT: I have only tested this with the 4DKNR motherboard (discrete ATI HD 5470 graphics) and an i7-740QM (S-spec SLBQG) processor with BIOS version A12. It may not work with other motherboards, CPUs or BIOS versions.

I have a number of theories as to why this was listed as unsupported:

• At the time, 8GB memory modules were very rare in the SODIMM form factor. The memory controller (integrated on the CPU die in the i7-740QM processor) only supports 2 memory sockets.
• Large-memory configurations were not that popular in Dell notebooks (at least in the Studio 1558 class) at the time. I’m told that the vast majority of Studio 1558s sold by Dell shipped with either 4GB (2GB * 2) or 6GB (4GB + 2GB) of installed memory.
• Dell sold the Studio 1558 with a wide variety of CPUs with either integrated graphics or discrete graphics. It is possible that some of the CPUs or motherboards were actually limited to 8GB and it was just easier to say that they all had an 8GB limit. That doesn’t explain the Intel Ark pages also being incorrect, though.

I did try a pair of 16GB modules (the CT204864BF160B) and they did not work – neither a pair of modules for a total of 32GB nor a single 16GB module in either the DIMM A or DIMM B socket were recognized – all resulted in the 4 beeps indicating “Memory read / write failure”. It is interesting that the error was not the 2 beeps of “No Memory (RAM) detected”, so the system definitely determined that there was memory installed, it just didn’t know how to deal with it. Given that a) We’re talking about trying to fit 32GB in a 10-year-old laptop, b) Most new laptops ship with 16GB or less, and even Dell’s current Alienware gaming laptops have more 16GB models than 32GB models, and c) The cost of a pair of Crucial CT204864BF160B modules, which works out to around US $300 at present, makes it economically impractical to do, since for $300 you can get a very nice whole used Studio 1558 with discrete graphics, 1920 x 1080 screen, etc. I think any further pursuit of this and related stunts like trying a Core i7-940XM is the computing equivalent of “They’ve gone to plaid!” (click the link if you don’t get the Hyperdrive joke from the movie “Spaceballs”).