Extending the Power of Hardware Profiles

Get maximum performance from your PC and useresources efficiently

Does your work often take you out of the office? Do you find yourselfworking in different settings, such as in a hotel room, on an airplane, or in a client's office? Do you sometimes need a network connection? At other times, do you wish you could turn off your PC Card to extend battery life on your laptop while you're working undocked? With hardware profiles, you can create multiple computer configurations for a specific hardware platform. With the advent of Windows NT on the laptop, Microsoft lets the user tell the operating system (OS) what devices to use on bootup and what devices to ignore.

Hardware profiles can help you get the best performance out of your PC. In September, Michael D. Reilly showed you how to configure hardware profiles for your computer in "Configuring Hardware Profiles." In this article, I will detail more ways to configure devices, help you overcome limited resource allocations, and show you how to configure services with hardware profiles.

Defining Hardware Profiles
Although hardware profiles debuted with Windows 95 as a way to control whatdevice drivers to load, NT takes them a step further. NT hardware profiles letyou determine not only what device drivers to load but also what services.Device drivers are the software interface between the OS and the peripheral orhardware. But services are a little more mysterious. In this article, think ofservices as software components that let the OS perform a specific softwaretask.

Services typically fall into two categories: OS applications and BackOfficeand third-party programs. OS applications consist of objects such as kernelvirtual device drivers (VxDs) and I/O Manager components such as the Workstationand Server services. When you install BackOffice applications such as Exchangeor SQL Server, these programs install applets that are viewable under theServices icon in Control Panel.

With the ability to choose both drivers and services, the user controlswhat peripherals and programs to start or disable. This situation opens up someinteresting scenarios for profiles. For example, laptop PC users can determinewhether they will use hardware devices such as the video adapter, network card,or CD-ROM in the docking station or whether they will operate undocked usingtheir laptop peripherals.

Also, laptop users can turn off (and remove) their PC Card to extendbattery life while the laptop is undocked. You have no reason to fire up your PCCard if you are working on an electronic spreadsheet while flying over theAtlantic and have no need for your network interface card (NIC) or modem. Youcan gain 30 minutes to 1 hour of battery up-time.

Administrators can run test configurations of BackOffice applicationswithout installing another instance of NT Server. (Wouldn't you like to installSQL Server, Exchange, and Internet Information Server--IIS--on one instance ofNT and not eat up all that hard disk space by installing NT three times?) And,for cards that use the same resources (such as IRQ, I/O ports), you can disableone card and enable the other to reach a stable configuration.

Hardware profiles give you a lot of options. But they also havelimitations. Perhaps the biggest limitation is the inability to add differentinstances of network services such as Domain Name System (DNS), protocols, orclients. For instance, if employees have a hard-coded IP address on their PCconfigured specifically for their network at their place of employment, theycannot plug their computer into another network across town that has a DynamicHost Configuration Protocol (DHCP) server configured and expect to automaticallybecome a DHCP client.

Selecting Startup Options
At startup, if you have only one profile, the OS loads that hardwareconfiguration without prompting you. This profile is the one that was saved whenyou last shut down your computer.

If you've configured multiple profiles, you have other choices at startup.After you select the OS via the boot.ini file, a screen similar to Screen 1appears asking you to select between the Last Known Good (LKG) configuration ora hardware profile configuration. You can use the up or down arrow to select anyhardware profile in the list, or press L to choose the LKG. NT willautomatically time out and default to the first profile in the profile list ifyou don't make a selection.

You can force the system to wait indefinitely for user intervention at thisscreen or time out to the first hardware profile in the list. To set thetimeout, open Control Panel, double-click System, and choose the HardwareProfiles tab shown in Screen 2. From the same window, you can manually edit theorder of the profiles list. Select a profile and use the up or down arrow in thedialog box to change the order.

Creating and Customizing Hardware Profiles
NT installs with a default profile, Original Configuration. This profilemaps to the hardware, drivers, and services you installed during the initialsetup. You can configure more profiles from the Hardware Profiles configurationwindow.

Let's look at the example in Screen 2. Moe has fine-tuned his laptop foroptimal hardware profile utilization. He has taken his default OriginalConfiguration and renamed it Docked at Work. This profile comprises all devicesin his docking station (NIC, Video Card, and keyboard) and does not include thetwo PC Cards (network adapter and modem) on his laptop. Because Moe occasionallytravels to other work sites that do not have a comparable docking station, hehas used the Copy button to reproduce the docked profile, renamed it, and thendisabled or enabled the appropriate devices under the Control Panel, Deviceswindow. To work at other sites, Moe can disable the docking station's NIC andenable his PC Card NIC.

In his September article, Mike Reilly tells you how to choose what profileis using a docking station so the expansion port that connects the laptop to thestation is properly used. For those times you won't be connecting to a network,you can create a profile to tell NT to ignore any network connections. To haveNT load as fast as possible, click the Properties button, and choose the Networktab. From the dialog box in Screen 3, you can tell NT to ignore any networkconnections. The OS will disregard any networked drives or printers thatautomatically reconnect at logon.

Configuring Devices for a Profile
Once you've initially configured profiles, you can open Control Panel tofurther define them by Device or Service. Let's work with Moe's Undocked atHome-2 PC Cards (2 Modems) profile.

Moe wants to use multilink support, which is the ability to combinemultiple links into one logical bundle, with the goal of increasing bandwidth.Because he has two PC Cards, he has to turn on the two devices for one profileand disable it for the others. From Control Panel, he double-clicks Devices tobring up the window in Screen 4, page 152. He scrolls down to Modem and clicksthe HW Profiles button. From the window in Screen 5, page 152, he can selecteach modem and enable it for the proper profile.

Suppose you've exhausted your computer resources such as IRQ, direct memoryaccess (DMA) channels, and I/O ports and you want to install a new card. I'veseen high-powered off-the-shelf PCs that have maxed out their resources. Withthe onslaught of new devices on the market, the demand to have it all has put astrain on interrupts in particular. Computers have a predefined limit of 15usable IRQs. However what happens when these IRQs are already assigned to yourperipherals and you want to add a new card to your PC? As long as you have aslot or bay to plug into, you might be able to add that device after all.

Suppose you want to install an internal 56KB modem in your PC. Afterinstalling the device, you discover that it conflicts with your previouslyinstalled NIC because both use Interrupt 10. Because interrupts typically do nothave provisions for sharing, you cannot get the new card to respond. If youdon't mind using only one device at a time, you will not have a problem. Simplycreate two profiles. On the NIC-enabled profile, enable the NIC and disable themodem card. On the modem-enabled profile, do the opposite. You can now reach astable configuration where each card can function, albeit only when the other isdisabled.

Configuring Services for a Profile
Being a Microsoft Certified Trainer (MCT) and having a limited budget, Ihave configured my home PCs to use hardware profiles in an effort to conserveboth RAM and hard disk space while I'm studying the latest BackOffice products.For example, I can install a common instance of NT for all my BackOfficeapplications as opposed to each BackOffice application having its own private OSinstance. This setup saves more than 100MB per OS instance.

I also don't eat up scads of RAM by loading all the services for SystemsManagement Server (SMS), Exchange, and IIS anymore. Because I have only 48MB ofphysical memory, I configure a different profile for each application so I don'toverwhelm the system.

To set up my home PC to use BackOffice hardware profiles, I initiallyinstalled IIS, SQL Server, and Exchange on NT. Things were pretty slow when NTwas loading all the services into RAM (you can use Task Manager to get a quicksnapshot of how much total memory the system is using) and the swap file startedkicking into gear. To remedy the situation, I created three profiles. I clickedon the Services icon in Control Panel to get the window shown in Screen 6. Ilocated the specific service I wanted to enable or disable and clicked the HWProfiles button.

Then, I enabled or disabled the service for each profile listed. In Screen 7, I've enabled the Exchange Mail Transfer Agent (MTA) service for the Exchange profile and disabled this service for IIS and SQL Server. When I repeated this procedure for all the appropriate services, I saw my system's performance increase dramatically.

One more use for profiles is for test conditions. For example, you can runBackOffice test configurations and conduct your benchmarks without having otherBackOffice programs interfere with your analysis. This capability isparticularly important when hardware is at a premium.

Maximizing Performance
This article digs into details about the role of hardware profiles. Althoughhardware profiles are optional, aspects of profiles can help you performancetune your PC, enable cards that would otherwise not work, and increaseflexibility in laptop configurations.